selector is a command line utility for dynamic string selection. As you type a list of substrings separated by ";" or a regexp, the display is updated in real time to show only the matching lines. The main usage of selector is as an efficient search in the shell command history. With the correct option, it will inject the selected line into the terminal input buffer, allowing the user to edit the line and execute it as a standard command.
rlimit is a program that lets you run processes with system resource limits set. It can be used by software developers and testers to test that software will run correctly in resource restricted environments. It is also useful for software which would otherwise consume excessive resources such as programs that used 100% CPU, set their own priority levels, or consume too much memory. This is basically a command line interface to the system functions getrlimit() and setrlimit().
PDFtk Server is a simple commandline tool for doing everyday things with PDF documents. You can use it to merge PDF documents or collate PDF page scans, split PDF pages into a new document, rotate PDF documents or pages, decrypt input as necessary (password required), encrypt output as desired, fill PDF forms with X/FDF data and/or flatten forms, generate FDF data stencils from PDF forms, apply a background watermark or a foreground stamp, report PDF metrics, bookmarks, and metadata, add/update PDF bookmarks or metadata, attach files to PDF pages or the PDF document, unpack PDF attachments, burst a PDF document into single pages, uncompress and re-compress page streams, and repair corrupted PDF files (where possible).
libpetey is a small scientific/numerical computation library. It includes the following components: templated sorting routines; templated binary tree classes; a templated linked-list class; routines for finding the k-least and k-greatest elements in an array; "supernewton", a powerful one-dimensional root-finding algorithm that combines bracketing with fast, superlinear convergence; a class for working with dates and times; a templated sparse matrix class; datasets (the beginnings of a data-representation paradigm that generalizes matrices, which is mostly useful for easy linear interpolation, especially generalized, n-dimensional linear interpolation); a function for easy parsing of command line options; and command-line utilities for sparse matrix multiplication and eigenvalue decomposition.