ccglue is a complementary tool to cscope and ctags. The tool builds a cross-reference symbol database from cscope (and ctags) databases that can be used to display dependency-graphs (aka call-trees, code flow). Visualization can be done with the Vim CCTree plugin or the built-in stand-alone command-line tracer.
Generic Makefile for C Projects is a generic makefile that builds a binary from C source code files. Any number of build modes are supported - Release and Debug are predefined. The CFlags and LFlags variables can be defined in a mode dependent way, i.e. CFlags_Debug. File dependencies are generated by the compiler (-MMD flag for preconfigured GNU compiler) and included by the makefile automatically. All output is written under a single target directory. It supports source files with the same name that are located in different directories. You can use wildcards to add any number of source files.
snappy-c is a C port of the google snappy compressor (http://code.google.com/p/snappy/). The compressor is very fast with a reasonable compression ratio. It is mainly useful for projects that cannot integrate C++ code, but want snappy. It also contains a command line tool, a benchmark, random test code, and a fuzz tester. The compression code supports scather-gather and linear buffers. The scather gather code is ifdefed (-DSG) and can be removed with unifdef.
cconstants is a library and a set of commandline utilities which allow the values of constants defined in C header files to be queried outside the C preprocessor. This allows the values of these constants to be queried from programming languages other than C, on systems without the C preprocessor installed, and on systems on which the header files defining these constants are not available.
s6-networking is a collection of small Unix tools designed to help networking. It includes clock synchronization, Unix and TCP super-servers, Unix and TCP access control, and other miscellaneous utilities. It is particularly suited for management of clients and servers on embedded devices, but works just as well on larger systems.