Hi, I'm Peter 👋

I have authored and/or currently maintain hundreds of open source libraries, including many you might use (as a developer or a consumer of the internet).

I recently worked on the Go project for dependency license scanning Apache SkyWalking Eyes, where I integrated bundler and gemspec (Ruby) compatibility, added ASF Category A and B license checks, FSF Free/Libre checks, and OSI Approved checks (all configurable). Learn how to use it in as a GitHub Action in your project.

I maintain the following RubyGems:

• appraisal-rb / appraisal2 -
• Dynamoid / dynamoid -
• galtzo-floss / flag_shih_tzu -
• galtzo-floss / sanitize_email -
• kettle-rb / tree_haver -
• kettle-rb / ast-merge -
• omniauth / omniauth-jwt -
• omniauth / omniauth-identity -
• rdp / os -
• ruby-oauth / oauth -
• ruby-oauth / oauth2 -
• ruby-oauth / version_gem -
• ruby-openid / omniauth-openid -
• ruby-openid / rack-openid -
• ruby-openid / ruby-openid -
• many ast-parsing, benchmarking, rails, resque, rspec, rubocop plugins & more... (in details below)

ast-parsing libraries

The *-merge Gem Family

The *-merge gem family provides intelligent, AST-based merging for various file formats. At the foundation is tree_haver, which provides a unified cross-Ruby parsing API that works seamlessly across MRI, JRuby, and TruffleRuby.

Gem	Version	CI		Language / Format	Parser Backend(s)	Description
tree_haver			Multi	Supported Backends: MRI C, Rust, FFI, Java, Prism, Psych, Commonmarker, Markly, Citrus, Parslet	Foundation: Cross-Ruby adapter for parsing libraries (like Faraday for HTTP)
ast-merge			Text	internal	Infrastructure: Shared base classes and merge logic for all *-merge gems
bash-merge			Bash	tree-sitter-bash (via tree_haver)	Smart merge for Bash scripts
commonmarker-merge			Markdown	Commonmarker (via tree_haver)	Smart merge for Markdown (CommonMark via comrak Rust)
dotenv-merge			Dotenv	internal	Smart merge for .env files
json-merge			JSON	tree-sitter-json (via tree_haver)	Smart merge for JSON files
jsonc-merge			JSONC	tree-sitter-jsonc (via tree_haver)	⚠️ Proof of concept; Smart merge for JSON with Comments
markdown-merge			Markdown	Commonmarker / Markly (via tree_haver)	Foundation: Shared base for Markdown mergers with inner code block merging
markly-merge			Markdown	Markly (via tree_haver)	Smart merge for Markdown (CommonMark via cmark-gfm C)
prism-merge			Ruby	Prism (prism std lib gem)	Smart merge for Ruby source files
psych-merge			YAML	Psych (psych std lib gem)	Smart merge for YAML files
rbs-merge			RBS	tree-sitter-bash (via tree_haver), RBS (rbs std lib gem)	Smart merge for Ruby type signatures
toml-merge			TOML	Parslet + toml, Citrus + toml-rb, tree-sitter-toml (all via tree_haver)	Smart merge for TOML files

Backend Platform Compatibility

tree_haver supports multiple parsing backends, but not all backends work on all Ruby platforms:

Platform 👉️ TreeHaver Backend 👇️	MRI	JRuby	TruffleRuby	Notes
MRI (ruby_tree_sitter)	✅	❌	❌	C extension, MRI only
Rust (tree_stump)	✅	❌	❌	Rust extension via magnus/rb-sys, MRI only
FFI (ffi)	✅	✅	❌	TruffleRuby's FFI doesn't support STRUCT_BY_VALUE
Java (jtreesitter)	❌	✅	❌	JRuby only, requires grammar JARs
Prism (prism)	✅	✅	✅	Ruby parsing, stdlib in Ruby 3.4+
Psych (psych)	✅	✅	✅	YAML parsing, stdlib
Citrus (citrus)	✅	✅	✅	Pure Ruby PEG parser, no native dependencies
Parslet (parslet)	✅	✅	✅	Pure Ruby PEG parser, no native dependencies
Commonmarker (commonmarker)	✅	❌	❓	Rust extension for Markdown (via commonmarker-merge)
Markly (markly)	✅	❌	❓	C extension for Markdown (via markly-merge)

Legend: ✅ = Works, ❌ = Does not work, ❓ = Untested

Why some backends don't work on certain platforms:

• JRuby: Runs on the JVM; cannot load native C/Rust extensions (.so files)
• TruffleRuby: Has C API emulation via Sulong/LLVM, but it doesn't expose all MRI internals that native extensions require (e.g., RBasic.flags, rb_gc_writebarrier)
• FFI on TruffleRuby: TruffleRuby's FFI implementation doesn't support returning structs by value, which tree-sitter's C API requires

Example implementations for the gem templating use case:

Gem	Purpose	Description
kettle-dev	Gem Development	Gem templating tool using *-merge gems
kettle-jem	Gem Templating	Gem template library with smart merge support

inherit_gem:
  rubocop-lts: rubocop-lts.yml # for ruby + rspec

TargetRubyVersion

I'm attempting to document all of the logos for the FLOSS projects I'm involved in, with their attendant licesnses and copyrights, here: logos.galtzo.com. It has been a multi-year effort hunting down the original creators for some of these logos, and documenting the conditions under which they can be used. I'd love to hear if this is useful in your projects!

I was laid off in a March 2025 RIF, and am looking for my next sponsor and my next role.

Want to chat about open source, or any of my projects? Join my FLOSS discord.

Or join the Ruby Friends Squad on Daily.dev

Want to pay me for work? I'm available!

Thanks to all my sponsors across any of the donation platforms! Special thanks to my biggest sponsor HealthSherpa!

• List is updated frequently by my pet robot: @autobolt

• 🗓️ 2025-11-08T11:51:49Z | oauth2 (2.0.18) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-11-07T02:41:43Z | oauth (1.1.3) | 🔑 A Ruby wrapper for the original OAuth 1.0 / 1.0a spec.
• 🗓️ 2025-10-21T07:54:03Z | undrive_google (1.1.2) | 🏴‍☠️ Liberate files from your Google Drive with transformations
• 🗓️ 2025-10-14T00:33:04Z | omniauth-identity (3.1.5) | 🫵 Traditional username/password based authentication system for OmniAuth
• 🗓️ 2025-09-22T03:02:52Z | oauth (1.1.2) | 🔑 A Ruby wrapper for the original OAuth 1.0 / 1.0a spec.
• 🗓️ 2025-09-22T02:52:36Z | oauth (1.1.1) | 🔑 A Ruby wrapper for the original OAuth 1.0 / 1.0a spec.
• 🗓️ 2025-09-21T11:21:48Z | oauth-tty (1.0.6) | 🖥️ OAuth 1.0 / 1.0a TTY Command Line Interface
• 🗓️ 2025-09-16T03:42:22Z | oauth2 (2.0.17) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-09-14T21:14:19Z | oauth2 (2.0.16) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-09-08T08:37:57Z | oauth2 (2.0.15) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-09-05T07:59:12Z | rspec-pending_for (0.1.19) | ⏳️ Mark specs pending or skipped for specific Ruby engine (e.g. MRI or JRuby) & versions, or version ranges. Fund overlooked open source projects - bottom of stack, dev/test dependencies: floss-funding.dev
• 🗓️ 2025-09-02T13:04:33Z | version_gem (1.1.9) | 🔖 Versions are good. Versions are cool. Versions will win.
• 🗓️ 2025-08-31T11:39:52Z | oauth2 (2.0.14) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-08-30T22:39:45Z | oauth2 (2.0.13) | 🔐 A Ruby wrapper for the OAuth 2.0 Authorization Framework, including the OAuth 2.1 draft spec, and OpenID Connect (OIDC)
• 🗓️ 2025-08-24T21:11:05Z | rspec-pending_for (0.1.18) | ⏳️ Mark specs pending or skipped for specific Ruby engine (e.g. MRI or JRuby) & versions, or version ranges. Fund overlooked open source projects - bottom of stack, dev/test dependencies: floss-funding.dev

• List is updated frequently by my pet robot: @autobolt

• 🗓️ 2025-11-06T23:39:10Z | 💲FLOSS Funding | 🏷️ career, discuss, opensource
• 🗓️ 2025-10-14T00:49:55Z | 💎 ANN: omniauth-identity v3.1.5 (Hanami/ROM Support) | 🏷️ webdev, ruby, rom, authentication
• 🗓️ 2025-09-18T06:30:38Z | 💎 ANN: oauth2 v2.0.17 | 🏷️ ruby, oauth, webdev, instagram
• 🗓️ 2025-09-15T11:53:14Z | 💎 ANN: kettle-dev v1.1.20 w/ improved CHANGELOG handling | 🏷️ devtools, ruby, packaging, automation
• 🗓️ 2025-09-14T23:07:29Z | 💎 ANN: oauth2 v2.0.16 w/ full E2E example (& Instagram Compat) | 🏷️ docker, security, ruby, instagram
• 🗓️ 2025-09-13T22:27:37Z | 👩‍🔧 How to Check License Compatibility in GHA | 🏷️ programming, opensource, githubactions, howto
• 🗓️ 2025-09-12T08:18:46Z | 💲ANN: awesome-sponsorships | 🏷️ opensource, webmonetization, sponsorships, programming
• 🗓️ 2025-09-01T03:24:45Z | 💎 ANN: oauth2 v2.0.14 | 🏷️
• 🗓️ 2025-08-30T23:13:42Z | 💎 ANN: oauth2 v2.0.13 | 🏷️ webdev, ruby, oauth, opensource
• 🗓️ 2025-08-27T03:39:03Z | 💎 ANN: stone_checksums v1.0.2 | 🏷️ programming, ruby, rubygems, security
• 🗓️ 2025-08-25T00:18:20Z | 💎 ANN: kettle-dev v1, part 1 | 🏷️ opensource, ruby, tooling, webdev
• 🗓️ 2025-08-22T07:55:13Z | 💎 ANN: kettle-test v1.0.0 | 🏷️ testing, ruby, rails, devtools

• 🦷 I'm putting more of my focus on FLOSS efforts (of myself and others)! and from
• 👷 I build big things and small things out of tiny bits.
• ✨ Recently created rubocop-lts for library maintainer happiness 👩‍❤️‍👩.
• 🔭 I’m working on finishing the migration away from TravisCI to modern CI tools.
• 🌱 I’m learning Svelte & SvelteKit, with Lucia, Drizzle, Zod, Inlang Paraglide, Skeleton, Tailwind, Typescript, and so many more cool tools.
• 👯 Preparing next release of seed_migrations and oauth gems!
• 🤔 I’ve moved my suite of Resque plugins to the Resque org!
• 📫 How to reach me
• 😄 Pronouns: He/Him
• 🗨️ I speak 3 languages fluently, and for a 4th I'm learning Bahasa Indonesia!
• 👷‍♂️ I help refugees and ex-refugees in Ghana🇬🇭 and Liberia🇱🇷, respectively, through Hope For Tomorrow, a Liberian NGO. DM me if interested in knowing more.

🛠️ My Dev Tools:

• The list is long, even in summary, see my LinkedIn.

• Open Source Contributor, OWASP | 🌪️ OWASP CycloneDX
• Open Source Contributor, ASF | 👀 Apache SkyWalking Eyes
• FLOSS Blogger | RailsBling
• FLOSS Author | RubyGems
• FLOSS Maintainer | Tidelift Enterprise OSS
• Researcher | WordTree Foundation