[ need to improve this introductory blather...]
Scheme is a clean and fairly small but powerful language, suitable for use as a general-purpose programming language, a scripting language, an extension language embedded within applications, or just about anything else.
Scheme was designed to lend itself to a variety of implementation strategies, and many implementations exist--most of them free software. There are straightforward interpreters (like BASIC or Tcl), compilers to fast machine code (like C or Pascal), and compilers to portable interpretive virtual machine code (like Java).
Several extended implementations of Scheme exist, including our own RScheme system, an extremely portable implementation of Scheme with an integrated object system and powerful extensibility features.
This is the first of three planned documents on Scheme, Scheme implementation, and the RScheme language and its implementation. When they're all finished, I may combine them into a big book. All three will be in Texinfo format, so that they can be printed out as hardcopy manuals, browsed online as info documents (with the Info browser, or the Info system for the Emacs editor), or converted automatically to HTML format for browsing with a web browser. Whichever way you're reading this, welcome to Scheme.
[ note: the current draft is only available in postScript form, because I haven't done all of the hyperlinking for the Info and HTML versions. ]