The first preview release of Ruby 2.6 is now available and its big change compared to its earlier releases is a just-in-time (JIT) compiler.

The Ruby 2.6 JIT compiler is designed to improve the performance of program execution -- its approach used is converting to C code, dumping to the disk, and uses a C compiler (GCC or Clang) to generate the native code.

There is still more work to do on the Ruby JIT, especially with regards to performance optimizations, but it's a starting point. The Ruby 2.6 preview release also has a new RubyVM::AST module, endless range support, and various other non-JIT related performance improvements.

More details on the new JIT support and other Ruby 2.6 preview features via Ruby-Lang.org.