A Java integrated, fully R5RS compliant Scheme system

 SISC is an extensible Java based interpreter of the algorithmic language
 Scheme. SISC uses modern interpretation techniques, and handily outperforms
 all existing JVM interpreters (often by more than an order of magnitude).
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 In addition, SISC is a complete implementation of the language. The entire
 R5RS Scheme standard is supported, no exceptions. This includes a full number
 tower including complex number support, arbitrary precision integers and
 floating point numbers, as well as hygenic R5RS macros, proper tail
 recursion, and first-class continuations (not just the escaping
 continuations as in many limited Scheme systems). SISC also attempts to
 implement the standard as correctly as possible, while still providing
 exceptional performance.
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 SISC also provides useful real-world extensions, such as networking, elegant
 exception handling, a scope-friendly module system, support for SLIB,
 numerous SRFIs, and a Java foreign-function interface.