More details can be found at Tcl Performance and Chart of proposed list functionality . Its use is an advanced optimisation technique that should be postponed if possible, since it does wonders for obfuscation Donal Fellows . The term is potentially confusing as other things are called library too, most notably bundled object code. A philosophy for developing, releasing, and evolving software. When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves.
People improve it, people adapt it, people fix bugs.
And this can happen at a speed that, if one is used to the slow pace of conventional software development, seems astonishing. An extension using tcl as implementation language. The defined commands are realized as tcl proc's. A piece of binary code that provides a set of operations and datastructures like a normal library, but which does not need to be physically incorporated into the executables that use it until they are actually executed. Virtually always implemented on machines with virtual memory by mapping the memory pages holding the library into the address space of each executable image in memory that uses the lib.