Tools, plugins, and utilities I have built for myself and others.
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Open a docker save tar or an OCI image layout and see each layer with its Dockerfile instruction and size, the merged file tree with what every layer added, changed and deleted, wasted space and dive's efficiency score, the config, the platforms in the index, every digest checked — and the packages inside, handed to the SBOM viewer.
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Lint Markdown with the real markdownlint rules (MD001–MD060, your .markdownlint.json) and AsciiDoc with structure checks that match Asciidoctor's warnings, with quick fixes — plus a table formatter for Markdown, AsciiDoc, CSV and TSV.
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Test EventBridge event patterns against events and see why each field matches or not — exact values, prefix and suffix (with equals-ignore-case), every anything-but form, numeric ranges, exists, IP CIDR, wildcards, $or and array semantics, following the AWS content-filtering rules — plus input transformers (InputPathsMap and InputTemplate) and a library of sample events.
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Paste iptables-save or nft list ruleset output and a packet, and step it through the netfilter hooks in the kernel's order — every chain, every rule tested with the reason it matched or didn't, jumps, returns, policies, DNAT and MASQUERADE — to the final verdict; with Docker's and kube-proxy's chains explained.
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Paste a GitHub Actions workflow: the job graph with a what-if-this-fails simulator, every matrix job after include/exclude, triggers with a branch/tag/path filter tester and next cron runs, a ${{ }} expression evaluator with an editable context, GITHUB_TOKEN permissions per job, concurrency groups, and actionlint's checks plus security checks.
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Render a Helm chart or a Kustomize overlay to plain YAML in the browser — with Helm's and Kustomize's own code compiled to WebAssembly — and see which values file or --set won each key, errors pointing at the template line, NOTES.txt, and what differs between two overlays.
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How a Java process fills a container's memory limit — heap, metaspace, code cache, thread stacks, direct buffers, GC structures and native memory — with the heap the JVM picks by itself on JDK 17, 21, 25 and 27, the flags that fit, OOMKilled versus OutOfMemoryError, and NMT output to fill it in.
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Read a JVM GC log — unified -Xlog:gc* for G1, ZGC (generational or not), Shenandoah, Parallel and Serial, or a JDK 8 PrintGCDetails log — and get a pause timeline, heap before and after, allocation and promotion rates, pause percentiles, throughput, full GCs and failures flagged, and tuning hints in plain words.
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Paste jstack, jcmd Thread.print, kill -3 or Thread.dump_to_file (text or JSON, with virtual threads) output: threads grouped by state and identical stack, deadlocks and a lock graph, thread pools, hot frames, CPU per thread, and a comparison of dumps taken seconds apart to find stuck threads.
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Paste NetworkPolicies, pods and namespaces (or kubectl get -o yaml output) and ask whether one pod can reach another on a port, with the policies that allow it or the reason it's blocked; a colour-coded pod × pod matrix, a lint, a policy builder, and a Pod Security Standards checker that lists every failing field and its fix.
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Paste your nodes and a pod or Deployment and see which nodes it can run on and why — every scheduler filter per node, the scores and weights that pick the winner, the FailedScheduling message, preemption victims, and N replicas placed one after another — checked against the real kube-scheduler v1.36.
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Paste the output of uptime, dmesg, vmstat, mpstat, pidstat, iostat, free, sar, top, /proc/meminfo, /proc/pressure, ss and cgroup files — several at once, in any order — and get a reading in the style of Brendan Gregg's 60-second checklist and the USE method: what each column means, what is abnormal, what to run next. Plus exit codes and signals (137 OOM-kill vs SIGKILL, 143) for Docker and Kubernetes.
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Paste or drop logs (large files are streamed) — nginx/Apache, JSON lines, logfmt, syslog RFC 3164/5424, journald, Java with multi-line stack traces, Go zap/slog, Kubernetes CRI, CloudWatch — or write a grok pattern with the standard Logstash library; get field statistics, a zoomable time histogram, filter expressions, message templates (Drain), CSV/JSONL export, and the table in DuckDB lab or the data wrangler.
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Paste a GNU Makefile and a list of files with their times: see what make -n would run and why, in order, with the recipes expanded; a dependency graph where you can touch a file; every rule and variable explained; and lints for missing .PHONY, spaces instead of tabs, $VAR in recipes and recursive-make pitfalls.
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Convert Markdown (GitHub-flavoured, with alerts, footnotes and front matter) to AsciiDoc and back, see both rendered side by side, and get a report of everything that had to be approximated.
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Open any property list — XML, binary (bplist00, every type including UIDs and dates), old-style OpenStep, `defaults read` output or JSON — edit it as a tree and get the plutil and defaults commands for each change, convert it byte-for-byte the way plutil does, take a binary plist apart, and browse a curated catalogue of defaults write tweaks with read and undo commands.
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Open a CycloneDX or SPDX SBOM, or a Trivy, Grype or OSV-Scanner report, and see the components by ecosystem with purls and licences (SPDX expressions parsed, copyleft flagged), the dependency graph, vulnerabilities by severity with fixed-in versions and "upgrade X to Y fixes N" suggestions — and what changed between two SBOMs.
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Size and price a serverless design — Lambda cost by memory, duration, requests and architecture (with the free tier, INIT billing and provisioned concurrency), concurrency from rate × duration against the account and scaling limits, cold-start factors, SQS batch and visibility-timeout checks with FIFO limits, Kinesis shards and on-demand against provisioned, SNS fan-out and API Gateway REST against HTTP — every price dated and sourced.
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Build a zsh PROMPT/RPROMPT and a bash PS1 from blocks — user, host, directory, git branch and state, exit status, time, venv — with a live preview in several terminal colour schemes; paste any prompt to see it expanded and explained escape by escape; and paste zprof or a timed xtrace log to find what makes zsh slow to start.
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Paste an Amazon States Language definition and see it drawn as a graph, checked for common mistakes, and run step by step with mocked Task results — every InputPath, Parameters, ResultSelector, ResultPath and OutputPath (or JSONata Arguments, Output and Assign) shown with the data it produced, intrinsic functions, variables, Retry with back-off, Catch, timeouts, Parallel and inline or distributed Map.
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Build a launchd job (LaunchAgent or LaunchDaemon) from a form, or paste one to have it explained and checked; turn crontab lines into StartCalendarInterval, see the next run times and what happens if the Mac sleeps through one, and get the launchctl bootstrap/bootout/enable/kickstart/print commands.
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Paste strace output — with or without -f, -tt/-ttt/-r, -T, -y/-yy, unfinished/resumed pairs, signals, -c tables — or macOS dtruss output, and get a per-thread timeline, a summary that matches strace -c, the slowest calls, errors grouped (path probing, EAGAIN loops), files with bytes read and written, connections and DNS lookups decoded from the buffers, the process tree with argv, and hints.
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Learn tmux by doing in a simulated tmux in the page — the real default keys, splits, layouts, zoom, windows, sessions, copy mode in vi or emacs keys, the command prompt, detach and attach — plus a .tmux.conf builder that explains every line, a live status-line preview, a layout-string decoder and encoder with the checksum, a searchable cheat sheet and how cmux compares.
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A real Linux booted in the page (a small kernel and BusyBox in the v86 x86 emulator) with a terminal, sample logs, CSVs and a config tree in your home directory, and 26 exercises — text pipelines, find and xargs, redirection, permissions, processes and signals, environment variables, loops — that check your answer.
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Paste a command line or a script and see it taken apart — pipes, redirections, && and ||, subshells, loops, quoting, variables, substitutions, globs and here-documents — with every option of 170 common commands explained, warnings for dangerous patterns such as rm -rf $DIR/ and curl | sh, and ShellCheck-style notes on common mistakes.
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Paste an nginx config or a Caddyfile and a request, and step through what the server does with it — which server block and location win and why, rewrites, try_files, if, alias vs root, the proxy_pass trailing-slash rules, add_header inheritance — ending in the file served, the upstream URL or the redirect. Plus a table of requests checked against expected outcomes.
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Printable safety cards and posters for each machine in a makerspace — A4 and A5 posters, A6 cards four to a sheet, or small Niimbot labels — with ISO 7010-style signs for PPE, hazards and rules, allowed and banned materials, key settings, who to ask, and a QR code that opens the machine's page and induction.
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Induct members on a makerspace's machines — a checklist the inductor ticks with them, a shuffled quiz with a pass mark, and a dated sign-off that expires when the machine says — with a register of who is signed off on what, expiring and expired sign-offs, CSV export, printable sign-off cards and member passports, a machine page for QR codes, and an editor for the space file.
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A lending desk for a makerspace's tool library — a catalogue with asset tags, check out by scanning the tool's QR code or typing its tag, due dates in the space's time zone, returns with a condition note, an overdue list, history per tool and per member, asset tags for the label maker and a QR sheet. Runs on one shared tablet; sync another device by file.
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Android Debug Bridge in the browser — over WebUSB or the network (port 5555 through the gitwebsite app): device info, logcat, a shell, APK install, apps, files, screenshots and recordings, and a TV remote for Fire TV and Android TV.
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Open agent traces — Claude Messages API and OpenAI Chat Completions or Responses logs, OpenTelemetry GenAI spans, Claude Code session JSONL — and see every turn, model call and tool call on a timeline and in a tree, with latency, tokens split into cache reads and writes, cost per step, failed tool calls and retries, and full-text search; nothing leaves the browser.
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Browse and query object stores and HDFS from the browser — S3, MinIO, R2, B2, Wasabi, GCS, Azure Blob and WebHDFS/HttpFS: buckets and folders, uploads with resumable multipart, Range downloads, presigned URLs, Parquet/ORC/Avro schema and row-group statistics, DuckDB SQL over files, HDFS block locations, bucket CORS/policy/lifecycle generators, and the aws/mc/gcloud/az/hdfs command and curl for every action.
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Draw a building floor by floor — walls with clean joins, doors, windows, stairs, rooms with their areas, dimensions, labels and scale-true furniture — over an imported plan image you calibrate and trace by hand or with automatic wall detection, see it in 3D, and export SVG, PNG, DXF (a layer set per floor) or JSON, or print it to scale.
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Build and explain nginx, Caddy, systemd and SSH configs — reverse proxies with Mozilla TLS settings, WebSockets and rate limits (with a limit_req simulation), static sites, hardened systemd services and timers with next run times and an exposure estimate, and ssh_config hosts and tunnels with a diagram — or paste your own and have each line explained and checked.
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Home Assistant from the browser (entities and history, a service caller built from each service's schema, a template tester, the event bus), an automation YAML linter and explainer, Shelly, Tasmota and Hue controls, and a Matter setup-code decoder and encoder.
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A phone-sized remote for LG webOS (SSAP and its pointer socket), Roku (External Control Protocol) and Samsung Tizen TVs on your network — apps, inputs, volume, text entry and toasts — plus developer-mode notes for each.
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Open the JSON of a Terraform or OpenTofu plan and see what it will create, change, replace and destroy — with why each replacement is forced, warnings for destroyed data stores, sensitive values masked, the attribute diffs as terraform plan prints them, and the dependency graph from the configuration's references.
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Draw an AWS architecture on an interactive diagram — VPCs, subnets and 40 services, from web tiers to data lakes, warehouses, stream processing and search — configure each service, see a rough monthly cost, and download a TypeScript AWS CDK app that synthesises.
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Paste a docker-compose.yml and see its services, networks, volumes, ports and depends_on as a diagram, the start-up order, the effective config after ${VAR} interpolation and profiles, and a kompose-style Kubernetes translation.
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A read-only dashboard for your own Docker and Kubernetes through a small local relay: containers, images, volumes and networks with live stats and logs; namespaces, workloads with rollout status, pods, services and endpoints, nodes, events, YAML, and a topology diagram — with every request copyable as curl, docker or kubectl.
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Paste a Dockerfile and see what every instruction does, which ones make layers, what a change rebuilds, how the stages connect and roughly how big the image is — with hadolint-style lints and one-click fixes.
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Draw a Google Cloud architecture on an interactive diagram — a project, its region and VPC network, and 37 mainstream services, including a big-data platform (warehouse, batch and stream processing) and a search and caching service tier — configure each service, see a rough monthly cost, and download Terraform that passes terraform validate.
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A git client in the browser: open a local repository (read-only unless you switch on write mode), see the commit graph, diffs, blame, file history, status and stashes; browse GitHub and GitLab repositories, pull requests and issues; clone over HTTPS through a relay you run.
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Learn git by doing: a terminal that runs real git commands against a faithful in-browser git (real SHA-1 object ids), with an animated commit graph, the three trees, the object database, a 34-lesson course with automatic goal checks, and disaster-recovery scenarios.
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An animated, step-by-step Linux host running Docker in your browser: docker run through dockerd, containerd and runc to clone(); namespaces, cgroups and the OOM killer; overlayfs copy-up and whiteouts; the build cache; pulling by digest from a registry; the bridge, veths, DNS and NAT; volumes; and the capabilities, seccomp and user namespaces that keep a container in — with a terminal that drives the same diagram.
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Build Kubernetes manifests from forms — Deployments to NetworkPolicies — with live YAML, checks across the whole bundle, kubectl-explain docs for every field, a CPU and memory unit converter with the QoS class your requests and limits produce, probe timelines and a CronJob schedule explainer.
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Build a docker run command from a form, or paste one and get every flag explained — ports, mounts, env, network, limits, healthcheck, security — with warnings, and convert it to a Compose service and back.
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Build kubectl commands with every flag explained; test label selectors against pods; try kubectl's JSONPath and custom-columns output on sample or pasted objects; and paste Roles and bindings to ask "can this user do that?", with the rule that grants it and a permissions matrix.
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Your phone as a compass — magnetic or true north, with the declination worked out for where you are by the World Magnetic Model — and a spirit level: a bullseye for flat surfaces, a tube for edges, two-sided calibration, a target angle that beeps, and the slope in degrees, percent, inches per foot and mm per metre.
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Clean and reshape tables with a recipe of steps — trim, retype, split, cluster near-duplicates, join, pivot, group — preview every step, then replay the recipe on new files or export it as SQL or pandas. DuckDB takes over for millions of rows.
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An experiment in connecting browser tools to Google Docs — sign in with Google, pick or create a document, read it, and append notes from a scratchpad (at the end, under a heading, or into a section a tool keeps up to date). The app can only see documents you pick or create here.
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Point your camera (or open a photo) at a plant, bird or insect and get the five most likely species — recognised on your device by Google's AIY Vision classifiers (2,101 plants, 964 birds, 1,021 insects), or rank your own labels with OpenAI's CLIP. Pictures never leave the page.
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Turn the tabs open in Chrome into a shareable link — drag tabs or bookmarks in, paste them, or load Chrome's bookmarks export, no extension needed — then edit titles, notes, a group name and colour, and re-share or open them.
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Measure an audio or video file's loudness in your browser — integrated, short-term and momentary LUFS (ITU-R BS.1770 / EBU R128), loudness range, true peak, sample peak, RMS, DC offset and clipping — compare it with YouTube, Spotify, Apple, podcast and broadcast targets, and export a normalised WAV.
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Dictate into notes kept in your browser. Speech is recognised locally with OpenAI's Whisper running in the page — the audio never leaves your device — or with the browser's own speech recognition, with live words as you speak.
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Read text or Markdown aloud on your own device — with your system's voices (word-by-word highlighting, rate, pitch, volume) or Kokoro, a neural voice model that runs in the browser — and download the speech as a WAV file.
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Grab a video's thumbnails and check your own at the sizes YouTube shows; build and validate chapters; make share links and privacy-enhanced embeds; count title, description, and tag limits; convert and fix SRT, WebVTT, and SBV captions and clean transcripts; time a script and run a teleprompter; and look up upload bitrates.
Article ·
The engine behind this site — a Rust static-site generator with a CLI, REST API, MCP server, and desktop app — is now on GitHub under the MIT licence.
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Turn images into ASCII, colour ANSI, or high-resolution Braille text art, and render FIGlet text banners in 30 fonts, ready to paste into terminals, READMEs, and source comments.
Article ·
How I connected a Mac to emulated and real Amigas over a serial link, built a source-level debugger and 129 MCP tools on top of it, and let Claude Code write, deploy, and debug Amiga software.
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Open CSV or TSV of any size in a fast scrolling table — sort, filter per column, search, column statistics, computed columns, and export to CSV, JSON, or Markdown.
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Beautify or minify JavaScript, TypeScript, JSON, CSS/SCSS/LESS, HTML, and XML, with indentation, wrapping, and brace-style options and before/after sizes.
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Check docker-compose.yml and Kubernetes manifests for mistakes that break deployments — unknown keys, bad references, port clashes, selector mismatches, removed API versions, invalid quantities — and convert crontabs to systemd timers.
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Explain, validate, and build cron expressions — Unix and Quartz/Spring syntax with L, W, # and macros — and see the next run times in any time zone.
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Convert between JSON, YAML, CSV/TSV, XML, TOML, and query strings, and generate TypeScript, JSON Schema, Go, Rust, and Python types from JSON.
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Live Graphviz (compiled to WebAssembly) and Mermaid editors, plus an AsciiDoc preview that renders [graphviz] and [mermaid] blocks inline and checks a gitwebsite post header — export SVG, PNG, or HTML.
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Searchable "how do I…" git recipes with safety notes, a .gitignore generator with a path tester, a Conventional Commits builder and linter, and .gitattributes and branch-name generators.
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Searchable HTTP status codes, headers, and methods; a REST API design guide; a MIME type table; a CORS cheat sheet; and a Cache-Control explainer.
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Resize, crop, rotate, and re-encode images as JPEG, PNG, WebP, or AVIF with a before-and-after comparison; strip EXIF; extract a palette; and build favicon and app-icon sets.
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Validate, format, minify, sort, and repair JSON; browse and edit it as a tree; query with JSONPath; transform with JavaScript; and diff two documents.
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Live side-by-side preview of Markdown (GitHub-flavoured) and AsciiDoc, with a table of contents, word count, HTML export, and HTML → Markdown conversion.
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ffmpeg compiled to WebAssembly, in your browser — convert, trim, crop, resize, rotate, re-time and watermark video; make GIFs and animated WebP; extract audio; split video into frames or build video from images; join clips; or run any ffmpeg command.
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Read text from photos, screenshots, scans and PDFs with Tesseract compiled to WebAssembly — clean up the image (threshold, deskew, upscale), pick a region, see every word's confidence, and export text, hOCR, TSV or JSON.
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Load any OpenAPI 3 or Swagger 2 description by URL, file, or paste; browse operations and schemas, fill in generated forms, send live requests, and check responses against the declared schemas.
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Make QR codes for links, Wi-Fi, contacts, email, SMS, phone numbers, and locations — with colours, logos, PNG and SVG — and read QR codes and barcodes from images or your camera.
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Format SQL for 18 dialects — PostgreSQL, MySQL, SQLite, T-SQL, BigQuery, Snowflake, Spark and more — with keyword case, indent style, and minify.
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Optimise SVGs with SVGO, convert them to PNG, data URIs, CSS backgrounds, and React/JSX components, and combine icons into a <symbol> sprite.
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Convert epoch seconds, milliseconds, microseconds, and nanoseconds to and from ISO 8601, RFC 2822, and other formats in any time zone, with a world clock and date arithmetic.
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Convert between the permission checkboxes, octal (755), and symbolic (rwxr-xr-x) modes — with setuid, setgid, sticky, umask, ls -l parsing, and ready-to-run chmod commands.
Article ·
How I built a modern dev kit for the 3DO Interactive Multiplayer — Norcroft ARM C in Docker, a patched Opera emulator with a GDB server and a JSON control port, and an MCP server — and used it to ship a demo and 21 games.
Project update ·
in gitwebsite
The first end-to-end build — content, areas, templates, and publishing to GitHub Pages.
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The app that builds and publishes this site — a Rust core with a CLI, a REST API, an MCP server for AI assistants, and a desktop app.
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A multi-project Claude Code orchestrator for macOS: it tracks the backlog of every project I work in and hands the next task to the right Claude session.
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A macOS menu-bar app that turns documents into PDF, plain text, spoken audio, and AI summaries through a pluggable pipeline — and can publish the results to Books, Music, Reading List, Obsidian, or Notion.
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A native analyzer for Claude Code session logs: it ingests every session into SQLite and shows how much reading, searching, and sub-agent work happened before code was written.
Article ·
A standalone JavaFX desktop app for inspecting and diagnosing Lucene indexes — documents, analyzers, and vector fields — as a desktop alternative to Luke.
Article ·
A local-first monitor for an off-grid 15 kW solar system that forecasts surplus power from the weather and tells you when to run heavy loads.
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A multi-language code analysis platform that turns repositories into a searchable graph of classes, functions, calls, and dependencies — with a REST API, a web UI, and an MCP server for AI assistants.
Project ·
A cross-development environment that connects a modern machine to an emulated or real Amiga over serial — live debugging, memory inspection, remote execution, and MCP tools so Claude Code can build and drive Amiga software.
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A local log search and analysis tool — Splunk-like search, facets, SQL, charts, and exports running entirely on your own machine, built on Java, Lucene, and Spring Boot.