SICStus Prolog is the de-facto standard industrial Prolog programming environment. With more than 25 years in fielded applications, it has a proven track record of a robust, scalable and efficient system. It is widely used for commercial applications as well as in research and education. This book edition contains the core reference documentation of SICStus Prolog release 4.3.0. SICStus Prolog complies with the ISO Prolog standard, IPv4, IPv6, and Unicode 5.0. It is interoperable with C, C++, .NET, Java, Tcl/Tk, Berkeley DB, ODBC, XML, MiniZinc, and more. It ships with a comprehensive library of modules for abstract data types, program development, operating system and file system access, processes, sockets, constraint solvers, and more. SICStus Prolog compiles to a virtual machine (WAM), emulated by efficient C code and compiled just-in-time to native code for x86-based platforms. Tools provide deployment to stand-alone, all-in-one-file, and embedded applications. The Eclipse-based development environment SPIDER provides semantics-aware editing support, static analysis tools, source-linked debugging, tracking variable bindings, profiling, code coverage, backtraces, call hierarchies, and more.