glark offers grep-like searching of text files, with very powerful, complex regular expressions (e.g., "/foo\w+/ and /bar[^\d]*baz$/ within 4 lines of each other"). It also highlights the matches, displays context (preceding and succeeding lines), does case-insensitive matches, and automatic exclusion of non-text files. It supports most options from the GNU version of grep.
p4delta works with a project that is in the Perforce configuration management system. It lists the local files that have been added, changed, or deleted. Content differences are summarized, i.e., the number of lines of code that have been added, changed, and deleted. It can also add, edit, and remove the appropriate files to/from Perforce.
DiffJ is a commandline application that compares Java files based on content, not whitespace, comments, or reordering of types, methods, or fields. Its output is based on the Unix program diff, and it also has a "brief" output format for a concise summary of what changed. It can work on directories recursively, looking for matching filenames, like "diff -r dir0 dir1". It is primarily for developers refactoring and reformatting Java code, for which most difference tools tend to produce misleading results regarding the type and extent of changes.
Coloryze is an application for generating color themes based on the theory of how hues can be combined. It supports monochromatic, complementary, split-complementary, double-complementary, analogous, and triadic schemes. It can generate tables for a full range of saturation and brightness values, or it can randomly select a group of colors to comprise a theme. It generates both text and HTML, and an online version is available.
Modifile is an application to modify the contents of text files, using Perl substitution expressions. Optionally, it can run interactively, with the user confirming substitutions to be made. It can also change file and directory names using the same expressions, and has hooks so that external programs (such as a checkout command) can be called for files that do not have write permission.
svndelta helps manage a Subversion project, identifying the local files that have been added, changed, or deleted. The relevant files can be automatically added to and removed from Subversion. A list of files is produced, with a summary of content differences, i.e. the number of lines of code that have been added, changed, and deleted.