hi, Lot of Mobile devices are coming with JVM with its OS(for example Nokia,sony ericcson).will all devices have same JVM? are all JVMs owned by sun micro systems? has device manufacturer paid for it to sun micro sytems? suppose If i want to creat my OWN JVM, I have to pay to sun micro sytems and get permission from SUN(ORACLE)? If it is not true, how sun gets profit?
+2
A:
Sun has published the specification of JVM. So other companies can write their own JVMs
Upul
2010-08-03 04:26:26
+4
A:
Sun of course owns the copyright for the Sun JVM, Hotspot, but this implementation is now licensed to the public under GPLv2, as part of OpenJDK. Further, Upul is correct that any company can implement the JVM Specification, and many have. Well-known implementations include Harmony, Jikes, and Kaffe. All of these have different levels of compliance with the specifications. Most device manufacturers still license the proprietary version of Hotspot from Sun directly.
Sun has restricted the Java Compatibility Kit, a set of tests used to prove compliance. However, even this has been loosened slightly. Now other implementations based on OpenJDK can more easily get JCK licenses.
However, this does not apply to independent free software implementations like Harmony. That is part of why Android chose not to try to implement Java fully, and instead made independent technical decisions that led them to Dalvik and a separate API.
Sun also holds patents, but they have not asserted them publicly.
Matthew Flaschen
2010-08-03 04:49:15
+2
A:
will all devices have same JVM?
No, definitely not. The fragmentation is terrible in the mobile Java world. Part of that fragmentation comes from all the different (and differently bugged, sadly) VMs.
are all JVMs owned by sun micro systems?
No, certainly not.
There are several companies writing Java VMs for cell phones. Esmertec used to be (and probably still is) one of them.
how sun gets profit?
That's one of the most problematic issue Sun faced during its pre-Oracle life: they've invented just so many great technologies (both hardware and software) but never really got enough profit from them. Java is a prime example of both a major Sun success and a major Sun failure.
Sun had, for example, machines where both the hardware and the OS was supporting CPU hot plugging literally decades before a similar thing will work (it still doesn't) in the "x86" world. That's just one example I'm thinking of.
Sun was made by geniuses, with geniuses, but they clearly where close to absolute-zero when it came to both marketing and selling the amazing stuff they came up with.
(I can think of at least one software company who's the total opposite: amazing marketing but crappy, insecure, bloated, underperforming software and the funny thing is that everyone knows which company I'm talking about ;)
NoozNooz42
2010-08-03 09:54:58