Programming languages history
- Historic Documents in Computer Science collected by Karl Kleine. Contains documents about some early versions of languages like Fortran, Algol, Simula, Bliss, ...
- History of LISP at the Computer History Museum has manual for early Lisps (LISP I, Lisp 1.5, Lisp 2, ...)
- Dennis Ritchier Home Page has a second on C and its immediate ancestors
- Bitsavers is a mine full of historic documents and software, some of those are related to programming languages (USCD Pascal for instance)