KScope is a KDE front-end to Cscope. It provides a source-editing environment for large C projects, such as the Linux kernel. [Open source, GPL]

CodeViz provides the ability to generate call graphs to aid the task of understanding code. [Open Source, GPL]

A tool for formatting C code. [Open source, GPL]

GNU cflow analyzes a collection of C source files and prints a graph, charting control flow within the program. [Open source, GPL]

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.

Cxref is a C source code cross referencing and documenting program for UNIX, written by Andrew M. Bishop. Cxref makes both html and latex style document.

An analysis and inspection tool that lets software developers and maintainers easily understand detailed dependence relations in source code.

Source code analyzer, detects problems compilers cannot catch, by Cleanscape Software.

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.

Supports a wide range of software development activities, from easy editing to controlling source quality, from detailed reviewing to documenting. By RistanCASE.