Noweb was written by Norman Ramsey and pointers to obtaining the source and binary distributions of noweb (among other related resources) can be found at his noweb homepage (http://www.cs.virginia.edu/~nr/noweb/).
The current source distribution contains both AWK and Icon versions of the library files necessary. The binary version is built from the Icon source and is recommended, as the Awk version lacks some of the default behavior of the Icon version. Norman Ramsey has informed us that he is no longer able to maintain and upgrade the Awk version.
Norman Ramsey has informed us of plans for version 2.8 to include a troff back end (in addition to TeX, LaTeX and HTML), conditional tangling and some pretty printing macros.