Ruby runtime MagLev 1.0 released
MagLev 1.0, an open source alternative Ruby virtual machine built on top of the 64-bit Smalltalk VM, GemStone/S, has been released. MagLev is developed by GemStone, who were acquired by VMWare in May 2010. MagLev is Ruby 1.8.7 compatible and takes advantage of the underlying VM's just-in-time compiler to provide native code performance. In an interview with InfoQ, lead developer Monty Williams explained that the key feature of MagLev was its integrated NoSQL data management capabilities. Williams said MagLev should be considered as a NoSQL database which used Ruby as its data manipulation language, with both working in a single object space.
It is able to store any Ruby object, including those representing execution such as procs, lambdas, threads and continuations, and can pass the executable stored objects between virtual machines where they can continue running. Maglev's source code is available in GemStone's github repository, from where it can be installed. There is also a MagLev installer script and support for installing with RVM (Ruby Version Manager).
The licensing of MagLev is somewhat complex. MagLev's Ruby code is under an MIT licence, but the GemStone VM is proprietary and the install scripts download and install an appropriate version (for Linux, Mac OS X or Solaris x86) and run it with a "free" key which enables a 2 GB shared cache. According to Williams, it does not limit the amount of data stored, only how much memory can be used to cache it. Users will need to pay if they want support or more cache. Williams assures potential users that "There will always be a free version".