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If anyone can give me brief information about the advantages and disadvantages of the two JVM since they all depend on the Standard JVM Specification.

staffan
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Richeve Bebedor
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3 Answers3

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JRockit was originally developed by Appeal and BEA Systems before being acquired by Oracle to run server software.1 It was meant to be optimized for large applications requiring long running tasks, a lot of memory and a scalable environment, pushing optimizations for these scenarios even further than the Sun HotSpot JVM in server-mode (see also: Real differences between "java -server" and "java -client"?).

Since the acquisition of Sun Microsystems by Oracle, Oracle has communicated on a concrete plan and roadmap to have JRockit and the HotSpot JVM to converge to be a "best of both worlds" implementation, mostly built on HotSpot but integrating the most popular features of JRockit.

In fact, and as mentioned on the same blog, JRockit won't be released as a Java 7 JVM; and some of JRockit's features are being incrementally brought into HotSpot (internally even sometimes now referred to as "HotRockit").

For more details, read:

1 As partially pulled from Wikipedia on March 3, 2012 at 1.50PM EST.

Community
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haylem
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  • @staffan: Did indeed mysstype that in the link, thank you :) Fixed. – haylem May 02 '12 at 15:27
  • It looks like this answer is a direct cut-and-paste from wikipedia. If this is indeed the case, attribution should be included in the answer. – mah Oct 14 '12 at 13:10
  • @mah: I actually checked because I would occasionally look up things on Wikipedia just like the next guy, but this one definitely isn't a copy paste. Or maybe I'm looking at the wrong page. That some of the information was researched with Wikipedia is quite likely (I don't remember, but the first paragraph probably partially was, or that was from the JavaOne 2010 and 2011 slides on the JRockit/HotSpot convergence), but the text and content itself definitely isn't a direct copy-paste from what I can see. Thanks for checking and keeping me on my toes though. – haylem Oct 15 '12 at 10:35
  • "from what I can see", you're not sure if you copy-pasted or not? – eis Jan 13 '14 at 17:55
  • @eis: "I actually checked because I would occasionally look up things on Wikipedia [...]". Honestly, no, I don't remember how I came to write this answer in 2012. I'm pretty confident I didn't just copy-paste it .Though I'd could have doubts about lifting content from Wikipedia or other sources, which I'd do, I'd also generally tend to link or cite these in my posts. I meant to say I took mah's remark into consideration in good faith and did go have a look to see if I shamelessly copied this, and from what I can see (because that describes it) here and on Wikipedia's history, I really didn't. – haylem Jan 14 '14 at 05:45
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    @eis: now feel free to [check](http://en.wikipedia.org/w/index.php?title=JRockit&action=history) if you don't believe me, and let me know if you find anything else apart from **a portion** of the 1st sentence (because, oh yeah, I might have read Wikipedia's entry to verify who was the original developer before Oracle, and not bothered to paraphrase the entirety of these 18 words. Sorry I researched and sourced the whole thing but but a contextual intro when I took a good 7 minutes to answer some guy asking for help on the intertubes. **This is now fixed. Please Resume life.** I sure did.) – haylem Jan 14 '14 at 06:03
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    @haylem I like how in your first response to _eis_ you worked yourself up over the need to explain/justify such silliness in the first place that your second response no longer fed the troll but trained the puppy. :) – Zayne S Halsall May 28 '16 at 09:35
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There is no JRockit release for java 7. The downloaded JDK for Java 7 and Java 8 is Java HotSpot. I can confirm this for Java 7 and Java 8 jdk downloads for oracle. Link for Java 7

Here is version confirmation for java -version for JDK 1.7
Java (TM) SE Runtime Environment (build 1.7.0_80-b15)
Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)

JRockit and HotSpot have been merged and JDK 7 contains the first release of this converged JVM (refer Henrik blog on Java 7)

sandk
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JRockit used to be regarded as better performing although I am not sure that was ever proved consistently. Oracle are currently merging JRockit and HotSpot.

Paul Medcraft
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