Freely available textbook by Torben Mogensen. It covers lexical and syntax analysis, symbol tables and type analysis, and code generation including register allocation and function calls.

Textbook by P.D. Terry, Rhodes University. Free online version in HTML and PDF, as well as source code to download.

Notes on compiler theory, the source code of describing actual construction of compiler in C programming language. Also compiler construction related links to books, notes, tutorials, and news groups.

For a compiler writer from P. J. Brown's Writing Interactive Compilers and Interpreters.

Links to resources for research in programming language theory, design, implementation, and related areas. (Mark Leone, Carnegie Mellon University)

A complete mini-course on Formal Languages and Automata