OpenJDK
Hacker ApprovedThe most recommended of 3 Java development kits
Free, open-source Java implementation that people use as their default JDK, praised for steady language and runtime improvements. Critics point to Oracle's influence and gaps against other JVMs.
Free, open-source Java implementation that people use as their default JDK, praised for steady language and runtime improvements. Critics point to Oracle's influence and gaps against other JVMs.
30 people gave an opinion
- recommend it
- 23
- criticize it
- 7
- approval share
- 77%
Recommended in 10 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: not recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: not recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 23 people recommend itNeeds 10 or more, met.
- 3.3 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 10 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Steady language and runtime improvements
“Java has seen a huge improvement both on the language and runtime front.”
Comment from 19 Jun 2026 in “Project Valhalla, Explained: How a Decade of Work Arrives in JDK 28” “OpenJDK is one of the best success stories of this.”
Comment from 30 Apr 2026 in “GCC 16 has been released” “I built a new telemetry framework into OpenJDK 26.”
Comment from 24 Feb 2026 in “Dissecting the CPU-Memory Relationship in Garbage Collection (OpenJDK 26)” - Comment from 20 Mar 2026 in “Java Is Fast. Your Code Might Not Be”
- Comment from 19 Jun 2026 in “Project Valhalla, Explained: How a Decade of Work Arrives in JDK 28”
- Comment from 14 Aug 2026 in “JDK 27 G1/Parallel/Serial GC Changes”
Default choice many people just use
“Personally I just use the OpenJDK builds provided by my linux distro and never give it a second thought.”
Comment from 1 Feb 2026 in “"Giving up upstream-ing my patches & feel free to pick them up"” “I've yet to run into a situation where I'd want to install anything except OpenJDK”
Comment from 28 Nov 2025 in “Installing Java in 2025, and Version Managers” “nowadays brew install openjdk@21 + adding path to shellrc is doing the trick”
Comment from 13 Feb 2026 in “Show HN: Kintsugi – A desktop app for reviewing Claude Code sessions” - Comment from 12 Dec 2025 in “Oracle made a $300B bet on OpenAI. It's paying the price”
Free open-source under Linux-style license
“made the open-source (same license as Linux) OpenJDK the reference implementation”
Comment from 3 Dec 2025 in “Anthropic acquires Bun” “completely open-source with the same license as the Linux kernel”
Comment from 21 Mar 2026 in “Java Is Fast. Your Code Might Not Be” “OpenJDK is free and libre.”
Comment from 10 Jul 2026 in “Java 27: What's New?” Professional, well-run open project
“There is just a high level of a professionalism around the whole project.”
Comment from 31 Jul 2026 in “JEP 401: Value Objects (Preview) merged to OpenJDK master” “OpenJDK is one of the best success stories of this.”
Comment from 30 Apr 2026 in “GCC 16 has been released”
What people warn about
Each mark is one comment
Oracle control and gatekeeping contributions
“It's not common for a random company to gatekeep contributions to a community project”
Comment from 1 Feb 2026 in “"Giving up upstream-ing my patches & feel free to pick them up"” “even OpenJDK is pretty much owned and controlled by Oracle”
Comment from 1 Feb 2026 in “"Giving up upstream-ing my patches & feel free to pick them up"” Behind other JVMs on some features
“This is only an issue on OpenJDK, other JVM implementations have had AOT tooling for quite some time.”
Comment from 18 Oct 2026 in “JDK 28” “GraalVM is better than OpenJDK”
Comment from 14 Aug 2026 in “What Garbage Collection Costs”
Other Java development kits people recommend
The two most recommended other Java development kits, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| OpenJDKThis page | 23 | 7 | 77% | 10 | — | Approved |
| JDK | 8 | 13 | 38% | 2 | — | — |
| Java Development Kit (JDK) | 6 | 3 | 67% | 4 | — | — |
What people said
All 36 comments that mention it, newest first. Each links to the original comment.
“This is only an issue on OpenJDK, other JVM implementations have had AOT tooling for quite some time.”
“the entire Java standard library on Android was switched from Apache Harmony to OpenJDK”
“you can get jvm and jdk from other vendors (eg: Red Hat)”
“Lower memory pressure is certainly a difficult thing to beat Go at, Java (OpenJDK) is probably never gonna get there.”
“openjdk decision to not support Apple intel”
“The JVM is an engineering marvel”
“granted the quality depends on which JVM is actually used”
“GraalVM is better than OpenJDK”
“the features found in OpenJDK or Dotnet”
“There is just a high level of a professionalism around the whole project.”
“good: openjdk (inherited)”
“OpenJDK is free and libre.”
“they have very refined tuning settings”
“the original documents are quite readable”
“Java has seen a huge improvement both on the language and runtime front.”
“At work, I have just witnessed a bug in JIT (it seems to have been fixed in OpenJDK 25).”
“OpenJDK is one of the best success stories of this.”
“the IntelliJ debugger with the OpenJDK is enough for me”
“I depise OpenJDK/Mono because of patents but at least they come with complete defaults”
“completely open-source with the same license as the Linux kernel”
“The openjdk can do fast startup pretty trivially.”
“just dump their hokey dalvik, ART, and other BS and just use the OpenJDK”
“Great post and great work. Keep it up.”
“I built a new telemetry framework into OpenJDK 26.”
“nowadays brew install openjdk@21 + adding path to shellrc is doing the trick”
“Personally I just use the OpenJDK builds provided by my linux distro and never give it a second thought.”
“It's not common for a random company to gatekeep contributions to a community project”
“even OpenJDK is pretty much owned and controlled by Oracle”
“Oracle cannot be blamed people are unable to understand the difference between OpenJDK and Oracle Java installers.”
“the online help always baits you into using OpenJDK which doesn't work for random stuff”
“Easy to trust if I'm on a windows system anyway”
“Where it's needed, an OpenJDK distribution is used.”
“made the open-source (same license as Linux) OpenJDK the reference implementation”
“I've yet to run into a situation where I'd want to install anything except OpenJDK”
“"-Djava.util.prefs.userRoot"), those too litter.”
“Getting OpenJDK ported is quite hard, congrats!”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.