overview

Io is a prototype-based programming language inspired by Smalltalk (all values are objects, all messages are dynamic), Self (prototype-based), NewtonScript (differential inheritance), Act1 (actors and futures for concurrency), LISP (code is a runtime inspectable/modifiable tree) and Lua (small, embeddable).

features

BSD license
small vm (~10K semicolons)
multi-state (multiple VMs in same process)
incremental collector, weak links
actor-based concurrency, coroutines
64bit clean C99 implementation
embeddable, exceptions, unicode

binaries

osx, windows, freebsd, openbsd, netbsd
linux x86rpm, x64rpm, x86deb, x64deb, raspberry pi armhf
binaries via jake peck

implementations

pypy, clr, jvm