WebKit/Chrome/V8 are leading the way in web standards implementation, with Firefox/Gecko/TraceMonkey also doing lots of great stuff.<p>Haskell is really taking off, both in terms of compiler improvements and in the size of the community and available libraries.  I'm using it for several projects now.<p>MagLev, LuaJIT, Unladen Swallow, and V8 (again) are all exciting because they're bringing modern dynamic language VMs closer to Java-like (and sometimes even C-like) speeds.<p>Android - my phone runs an open source OS, I can install software on it without an app store, and it can run SSH, Python, and Lua.  Sweet!