iesd is a shell based daemon that uses Linux cgroups (cpu and blkio) to improve the responsiveness of the user's workstation. Inspired by both the "200 line kernel wonder patch" and "shell four liner", this shell daemon was written so that any kernel that supports cgroup cpu can bring benefits to the user.
Rerun is a lightweight tool-building framework useful to those implementing management procedure with shell scripts. It will help you organize your implementation into well-defined modular interfaces. Collections of management modules can be archived and delivered as a single executable to facilitate team handoffs. Using the "stubbs" module, rerun will even facilitate unit tests. When users execute rerun module commands, rerun can record execution data into log files which can later be replayed.
Pipa reads data from stdin and does various things with it: rotates by time interval / output file size; compresses it (gz, bz2, lzo, xz); names the output file with strftime(); splits it intelligently when given info about the file structure (newlines / PCAP); calls a user command on the finished output file; passes it to stdout (like tee); and more.
Dateutils are a bunch of tools that revolve around fiddling with dates and times in the command line, with a strong focus on use cases that arise when dealing with large amounts of financial data. Their target market is shell scripts that need date calculations or calendar conversions, and as such they are highly pipe-able and modeled after their well-known cousins (e.g. dtest vs. test, or dgrep vs. grep).
getxbook is a collection of tools to download books from websites. There are tools to download from Google Books' "book preview", Amazon's "look inside the book", and Barnes and Noble's "book viewer". There is an optional GUI written in Tcl/Tk, and some shell scripts using OCR to create plain text or searchable PDFs and DjVu files from the downloaded books.
PirateWall is a simple Twitter Client. It displays search results for a certain keyword or hashtag in realtime in a shell-based environment. It can also be configured to act as a data provider for many different visualization tools. For example, it is possible to use the client as a text generator for many XScreensaver applications like "apple2" or "starwars". When used in a Unix shell environment, colorized output can be generated.