The lptools suite provides a complete, programming-language independent, literate programming environment. The suite targets XML documentation, but the underlying system has no bias that would disadvantage other documentation languages. It also includes a programmable build tool (a replacement for 'make') that can handle very complex and dynamic dependency graphs.
wyoGuide is a tutorial, a collection of guidelines for building cross-platform applications with a well-designed, consistent look and feel. It gives ideas and advice on how an application and its GUI could and should be written. Development with these guidelines gives the GUI of an application a standard set of base functionality. wyoGuide also provides sample code for each guideline written in C++ using the wxWidgets (formerly wxWindows) framework. For a seasoned developer it shouldn't be difficult to adapt these guidelines to other languages or frameworks.
cstor is a cross-reference compiler and reverse engineering tool. It compiles one text file (database) from multiple source modules (currently reads C, C++, and Perl). The tool combines reverse engineering capabilities, code validation, and an HTML documentation generator. The database can then be reused from own scripts and programs, e.g. to implement cross-compilers, validate coding conventions, build statistics etc. The builtin documentation generators are actually an application of the database.
Daikon is an implementation of dynamic detection of likely invariants. An invariant is a property (such as "x=2*y+5" or "this.next.prev = this" or "myarray is sorted by <") that holds at a certain point or points in a program. Invariants are often seen in assert statements, documentation, and formal specifications. Invariants can be useful in program understanding and a host of other applications. Daikon runs a program, observes the values that the program computes, and then reports properties that were true over the observed executions. It can detect properties in Java, C, C++, Perl, and IOA programs, in spreadsheet files, and in other data sources.