Charles Oliver Nutter
@headius.bsky.social
JRuby co-lead, Java champion, Ruby hero, JavaOne Rockstar, international traveler and speaker. Book me for your next event! I depend on your donations and sponsorships! https://github.com/sponsors/headius
Just a few weeks left until RBQ Conf in Austin! My first trip back since Keep Ruby Weird in 2016. Looking forward to catching up with the local community and showing the latest and greatest JRuby use cases! Here's a discount code for rbqconf.com : ShareTheRBQ
RBQ Conf
RBQ Conf is a regional Ruby gathering where code meets community, with meaty talks, saucy insights, and plenty of time to connect. Coming to Austin, TX on March 26 & 27, 2026.
rbqconf.com
February 13, 2026 at 2:51 PM
Just a few weeks left until RBQ Conf in Austin! My first trip back since Keep Ruby Weird in 2016. Looking forward to catching up with the local community and showing the latest and greatest JRuby use cases! Here's a discount code for rbqconf.com : ShareTheRBQ
I have a collection of video game equipment from the past 50ish years, ranging from a Magnavox Odyssey to a Neo Geo. I'm always looking for working hardware and games if you're looking to declutter. Notable gaps: Sega Saturn, Nomad, and MS; Famicoms; TG16 or express. Let me know!
February 4, 2026 at 1:17 AM
I have a collection of video game equipment from the past 50ish years, ranging from a Magnavox Odyssey to a Neo Geo. I'm always looking for working hardware and games if you're looking to declutter. Notable gaps: Sega Saturn, Nomad, and MS; Famicoms; TG16 or express. Let me know!
Reposted by Charles Oliver Nutter
JRuby 10.0.3.0 is released! Over 80 issues and pull requests and 13 external contributors combined to help further stabilize our 10.0 series! There's lots of compatibility fixes, a few performance enhancements, and a number of library updates. Upgrade is recommended!
www.jruby.org/2026/02/02/j...
www.jruby.org/2026/02/02/j...
JRuby 10.0.3.0 Released — JRuby.org
www.jruby.org
February 3, 2026 at 1:40 AM
JRuby 10.0.3.0 is released! Over 80 issues and pull requests and 13 external contributors combined to help further stabilize our 10.0 series! There's lots of compatibility fixes, a few performance enhancements, and a number of library updates. Upgrade is recommended!
www.jruby.org/2026/02/02/j...
www.jruby.org/2026/02/02/j...
I don't know how Windows users tolerate it at this point. I'm trying to install Windows 11 on a fairly recent, mainstream machine here. It won't recognize the SSD without additional drivers. The drivers are only distributed as an exe file.
February 2, 2026 at 6:29 PM
I don't know how Windows users tolerate it at this point. I'm trying to install Windows 11 on a fairly recent, mainstream machine here. It won't recognize the SSD without additional drivers. The drivers are only distributed as an exe file.
Why is the GitHub Milestone view so completely useless? If you have a mix of PRs and issues you can't make changes, no way to sort or further filter. It should link to a filtered search, issues and PRs should be modifiable in bulk from any view. These limitations just baffle me.
January 30, 2026 at 7:54 PM
Why is the GitHub Milestone view so completely useless? If you have a mix of PRs and issues you can't make changes, no way to sort or further filter. It should link to a filtered search, issues and PRs should be modifiable in bulk from any view. These limitations just baffle me.
A portion of Ruby's keyword arguments handling reduced to a very large ternary. This just decides whether to dup the incoming keywords hash, whether to set old-style keywords flags, and what to use for actually setting local variables. It's so easy!
gist.github.com/headius/d015...
gist.github.com/headius/d015...
Ruby keyword arguments processing is so simple
Ruby keyword arguments processing is so simple. GitHub Gist: instantly share code, notes, and snippets.
gist.github.com
January 28, 2026 at 11:05 PM
A portion of Ruby's keyword arguments handling reduced to a very large ternary. This just decides whether to dup the incoming keywords hash, whether to set old-style keywords flags, and what to use for actually setting local variables. It's so easy!
gist.github.com/headius/d015...
gist.github.com/headius/d015...
I've finally started working on the FFI bindings for the RBS Ruby static type annotation library! Pretty far out of my comfort zone, but I have a dynamic library building and basic entry points binding. Unexplained segv has me stuck. Help wanted!
github.com/ruby/rbs/pul...
github.com/ruby/rbs/pul...
FFI support by headius · Pull Request #2572 · ruby/rbs
This PR will build out support for loading the RBS library via FFI, avoiding the C extension on implementations that don't support the CRuby extension API.
github.com
January 27, 2026 at 6:21 AM
I've finally started working on the FFI bindings for the RBS Ruby static type annotation library! Pretty far out of my comfort zone, but I have a dynamic library building and basic entry points binding. Unexplained segv has me stuck. Help wanted!
github.com/ruby/rbs/pul...
github.com/ruby/rbs/pul...
With tons of help from @enebo.bsky.social, I have been cleaning up JRuby's support for using the "Prism" Ruby parser powered by the Chicory WASM runtime! This will allow us to maintain Ruby language compatibility without a native library requirement. Wild stuff!
Integrate WASM-based Prism parser into standard build by headius · Pull Request #9184 · jruby/jruby
This continues the integration of Prism parser wrapper libraries from the jruby-prism project by shading it in and including the new WASM support and Chicory libraries. This is a prototype of how i...
buff.ly
January 22, 2026 at 4:00 PM
With tons of help from @enebo.bsky.social, I have been cleaning up JRuby's support for using the "Prism" Ruby parser powered by the Chicory WASM runtime! This will allow us to maintain Ruby language compatibility without a native library requirement. Wild stuff!
Ugh, TFW HotSpot's tiered compilation mode runs a complex library way slower enabled than disabled. PrintCompilation and LogCompilation don't tell me much. Probably need to go to the graph?
January 22, 2026 at 7:30 AM
Ugh, TFW HotSpot's tiered compilation mode runs a complex library way slower enabled than disabled. PrintCompilation and LogCompilation don't tell me much. Probably need to go to the graph?
Spring conferences are coming together! No JavaOne for me again so my first stop will be Austin Texas for RBQ in March (get tickets now!), then Wroclove.rb and RubyKaigi in April and RubyConf Austria in May. Hope to meet you somewhere in the world!
rbqconf.com
rbqconf.com
RBQ Conf
RBQ Conf is a regional Ruby gathering where code meets community, with meaty talks, saucy insights, and plenty of time to connect. Coming to Austin, TX on March 26 & 27, 2026.
rbqconf.com
January 21, 2026 at 3:53 PM
Spring conferences are coming together! No JavaOne for me again so my first stop will be Austin Texas for RBQ in March (get tickets now!), then Wroclove.rb and RubyKaigi in April and RubyConf Austria in May. Hope to meet you somewhere in the world!
rbqconf.com
rbqconf.com
JRuby 10.1 is just a few dozen tests away from being Ruby 4.0 compatible. We should be able to release in the next few weeks. Feels good to stay caught up and get our recent performance work out to users along with up-to-date compatibility!
January 13, 2026 at 11:24 PM
JRuby 10.1 is just a few dozen tests away from being Ruby 4.0 compatible. We should be able to release in the next few weeks. Feels good to stay caught up and get our recent performance work out to users along with up-to-date compatibility!
Anyone who claims LLMs are going to replace all developers is ignoring the fact that they can only generate code based on existing examples that depend on APIs, runtimes, and kernels that are original and unique. Is your LLM writing apps in assembly? Yeah, didn't think so.
January 10, 2026 at 9:13 PM
Anyone who claims LLMs are going to replace all developers is ignoring the fact that they can only generate code based on existing examples that depend on APIs, runtimes, and kernels that are original and unique. Is your LLM writing apps in assembly? Yeah, didn't think so.
The 2026 season of First Robotics Challenge looks like a banger! Lots of chaos with ball-shooting, scoring phases, and a single climbing tower. Headius Enterprises will sponsor our local team...more details on that soon! www.firstinspires.org/resources/li...
Season Materials | FIRST Robotics Competition
Access official FIRST Robotics Competition game materials, robot build kits, and resources to help your team design, build, and compete with confidence.
www.firstinspires.org
January 10, 2026 at 5:30 PM
The 2026 season of First Robotics Challenge looks like a banger! Lots of chaos with ball-shooting, scoring phases, and a single climbing tower. Headius Enterprises will sponsor our local team...more details on that soon! www.firstinspires.org/resources/li...
Today I'm I enjoying my Golden Yunnan tea from Rishi, similar to English Breakfast tea but earthier and more flavorful.
I also got samples of their Pu'er and Wild Thai teas. The tea quality from Rishi is hard to beat and emboldens me to try new things.
buff.ly/TkEbz4s
I also got samples of their Pu'er and Wild Thai teas. The tea quality from Rishi is hard to beat and emboldens me to try new things.
buff.ly/TkEbz4s
Rishi Tea & Botanicals
Rishi Tea & Botanicals is an online tea shop with a wide variety of loose leaf, sachet teas, tea gifts, teaware, and botanical ingredients. We are a Direct Trade importer of premium, organic teas and…
buff.ly
January 9, 2026 at 9:26 PM
Today I'm I enjoying my Golden Yunnan tea from Rishi, similar to English Breakfast tea but earthier and more flavorful.
I also got samples of their Pu'er and Wild Thai teas. The tea quality from Rishi is hard to beat and emboldens me to try new things.
buff.ly/TkEbz4s
I also got samples of their Pu'er and Wild Thai teas. The tea quality from Rishi is hard to beat and emboldens me to try new things.
buff.ly/TkEbz4s
Welcome to Trump's America. Drink as much as you want, because you're either getting deported or killed. 🇺🇸
January 9, 2026 at 7:50 AM
Welcome to Trump's America. Drink as much as you want, because you're either getting deported or killed. 🇺🇸
Who would have thought that hiring and arming a bunch of MAGA thugs to be unrestrained, masked immigration bounty hunters would lead to the murder of citizen protesters? 🙄
January 9, 2026 at 12:07 AM
Who would have thought that hiring and arming a bunch of MAGA thugs to be unrestrained, masked immigration bounty hunters would lead to the murder of citizen protesters? 🙄
Running my own business has given me new respect for corporate bookkeepers who used to chase me around for expense receipts. 😩
January 8, 2026 at 6:15 PM
Running my own business has given me new respect for corporate bookkeepers who used to chase me around for expense receipts. 😩
Really hoping I can join RBQ in Austin this March with a snazzy new talk about cool JRuby use cases! The CFP closes tomorrow, don't miss out!
rbqconf.com
rbqconf.com
RBQ Conf
RBQ Conf is a regional Ruby gathering where code meets community, with meaty talks, saucy insights, and plenty of time to connect. Coming to Austin, TX on March 26 & 27, 2026.
rbqconf.com
January 6, 2026 at 7:02 PM
Really hoping I can join RBQ in Austin this March with a snazzy new talk about cool JRuby use cases! The CFP closes tomorrow, don't miss out!
rbqconf.com
rbqconf.com
Inspired by Maciej's work in buff.ly/Pp5PKvT, I've attempted to integrate into JRuby a Java implementation of Daniel Lemire's fast float parsing. Early results are as much as 16x faster than the crusty old impl we currently have!
Use FastDoubleParser where appropriate by headius · Pull Request #9150 · jruby/jruby
This hooks up the FastDoubleParser project to our internal float parsing logic, excluding cases that are not 7-bit ASCII or which contain underscore characters (not currently allowed by FDP, see wr...
buff.ly
December 28, 2025 at 6:10 AM
Inspired by Maciej's work in buff.ly/Pp5PKvT, I've attempted to integrate into JRuby a Java implementation of Daniel Lemire's fast float parsing. Early results are as much as 16x faster than the crusty old impl we currently have!
Not sure which job is more repellant.
December 28, 2025 at 1:00 AM
Not sure which job is more repellant.
If I were to do a 1.5 hour workshop on JRuby, what would you most want to learn? Performance and optimization? Deploying Ruby apps on Java servers? Calling into other libraries on the JVM? JVM tools for profiling and monitoring? Hacking on JRuby itself?
December 26, 2025 at 4:39 AM
If I were to do a 1.5 hour workshop on JRuby, what would you most want to learn? Performance and optimization? Deploying Ruby apps on Java servers? Calling into other libraries on the JVM? JVM tools for profiling and monitoring? Hacking on JRuby itself?
I'm super excited to peak here for the first time and meet the local Ruby community! We will have a big new JRuby release by then with 4.0 compatibility and a bunch of optimizations.
Psst... see this gift under the Christmas tree? Let's unbox it 🎄
@headius.bsky.social joins us at #wrocloverb to show how you can level up your Ruby with JRuby - bringing true parallelism, pauseless garbage collection, and JIT optimizations to your Rails apps.
This one’s a real treat! 🎁
@headius.bsky.social joins us at #wrocloverb to show how you can level up your Ruby with JRuby - bringing true parallelism, pauseless garbage collection, and JIT optimizations to your Rails apps.
This one’s a real treat! 🎁
December 24, 2025 at 11:01 PM
I'm super excited to peak here for the first time and meet the local Ruby community! We will have a big new JRuby release by then with 4.0 compatibility and a bunch of optimizations.
A JRuby user upgrading an old app recently filed a bunch of bugs about poor perf versus CRuby. In almost every case, it was an optimization or logic change we never knew about, and once added JRuby is faster. If something isn't as fast in JRuby as in CRuby, it's a bug. Report it!
December 20, 2025 at 7:33 PM
A JRuby user upgrading an old app recently filed a bunch of bugs about poor perf versus CRuby. In almost every case, it was an optimization or logic change we never knew about, and once added JRuby is faster. If something isn't as fast in JRuby as in CRuby, it's a bug. Report it!
I would bet money that Google et al have been dumbing down their existing non-LLM services to force people to use their LLMs. Now that Gemini is offered to replace Google Assistant, the latter has become FAR worse, failing simple queries and commands. Class-action suit incoming?
December 18, 2025 at 8:17 PM
I would bet money that Google et al have been dumbing down their existing non-LLM services to force people to use their LLMs. Now that Gemini is offered to replace Google Assistant, the latter has become FAR worse, failing simple queries and commands. Class-action suit incoming?
I just tried to use ChatGPT to generate a switch to compare a byte[] with a set of strings, switched on the length of the string and then equality checks. The code looked right, except all of the sizes were totally wrong.
Lesson learned: don't use LLMs for anything numeric.
Lesson learned: don't use LLMs for anything numeric.
December 16, 2025 at 11:23 PM
I just tried to use ChatGPT to generate a switch to compare a byte[] with a set of strings, switched on the length of the string and then equality checks. The code looked right, except all of the sizes were totally wrong.
Lesson learned: don't use LLMs for anything numeric.
Lesson learned: don't use LLMs for anything numeric.