ccache:Acts as a caching pre-processor to C/C++ compilers, which often results in a 5 to 10 times speedup in common compilations. [Open Source, GPL]
ASTREE: A static analyzer analyzes reactive, critical, real-time programs written in the C programming language and looks for runtime errors. All possible errors are detected by the analyzer, with minimal "false alarms".
C Module Viewer (CMV): A small and smart programming tool that supports software engineering under C in the subjects modularity, overview and navigation (for Windows 9x/NT/2000). By Ezer Programmings.
C to Java converter: Convert C preprocessed source to Java.
CC Shell: Allows C source files to be directly executed as scripts (using #!), speeding development and simplifying maintenance.
CCured: Source-to-source translator for C, which analyzes the program to determine the smallest number of run-time checks that must be inserted in the program to prevent all memory safety violations.
CodeSurfer: An analysis and inspection tool that lets software developers and maintainers easily understand detailed dependence relations in source code.
CodeViz: CodeViz provides the ability to generate call graphs to aid the task of understanding code.
Compilercache: Caches compiled object files to dramaticly speed up compiles. More convenient than make, and speeds up builds (like RPM builds) that make doesn't. Obsoleted by ccache.
Crystal C/C++ Suite: A suite of C/C++ review, visualization and editing tools: Flowcharts, Tokens Panel, Comment Generator, and Auto-Formatting in real time, call/caller/file graphs.
Development Assistant for C: Supports a wide range of software development activities, from easy editing to controlling source quality, from detailed reviewing to documenting. By RistanCASE.
Exuberant Ctags: Generates an index (or tag) file of C language objects found in C source and header files that allows these items to be quickly and easily located by a text editor or other utility. [Open Source, GPL]
GNU GLOBAL: GNU GLOBAL is a source code tag system that works the same way across diverse environments.
Indent: A tool for formatting C code. [Open source, GPL]
Insure++: An error detection tool for C/C++ that automatically finds hidden errors at the source code level.
LCLint: Tool for statically checking C programs, GPL.
Lint Plus: Source code analyzer, detects problems compilers cannot catch, by Cleanscape Software.
Myer: Colorizes identifiers and constants to show their marginal cost to the program's coupling and cohesion metrics. [GPL]
Splint: Splint is a tool for statically checking C programs for security vulnerabilities and coding mistakes.
The Codist: Check this site for a survey of source code comprehension tools (these show flow and/or relationships of function within the program in a graphical and/or text manner). Both free and commercial products are listed.