Other Tools
The previously listed applications are just the tip of the iceberg when it comes to developing C applications. Due to the language's popularity, dozens of excellent and free other tools are available. Each takes a little effort to learn, but once you master them, they should improve the quality of your C programming and applications.
Eclipse
Eclipse is an open source development environment written in Java, meaning it will run on practically every operating system. Although its initial purpose was for creating Java applications, by adding the C/C++ plug-in (see www.eclipse.org/tools/downloads.html), you can create C programs, too.
Splint
Splint, short for Secure Programming Lint, helps to check your C applications for security concerns and other mistakes. It abides by the C99 standard and has a pretty good manual. Splint is freely available and can be run on most operating systems.
C Beautifier (cb)
cb is a special utility whose sole purpose is to reformat C code in a consistent style. You should probably back up a file before using one of these utilities for the first time, but the experience may give you a better appreciation for a professionally formatted document. One of the other features is to replace tabs—which are easier to type—with spaces—which are more portable. Of the available versions of cb, one is bcpp (http://freshmeat.net/projects/bcpp/).