femtolisp

femtolisp is a simple, elegant Scheme dialect. It is a lisp-1 with lexical scope. The core is 12 builtin special forms and 33 builtin functions. It is fast, ranking among the fastest non-native-compiled Scheme implementations. It achieves this level of speed even though many primitives (e.g. filter and for-each) are written in the language instead of C. femtolisp uses a bytecode compiler and VM, with the compiler written in femtolisp. Bytecode is first-class, can be printed and read, and is "human readable" (the representation is a string of normal low-ASCII characters).

FEATURES

• vectors, strings, gensyms
• backquote
• exceptions
• printing and reading circular/shared structure
• all values can be printed readably
• prettyprinting
• hash tables
• support for directly using C data types ala Python's ctypes
• equal and ordered comparison predicates that work on circular structure
• proper tail recursion
• io and memory streams with utf8 support
• highly compatible with Scheme, including some R6RS features
• simple, well-organized, powerful API with as few functions as possible
• compacting GC