The Assimilation Monitoring Project is a highly scalable discovery-driven monitoring system. It integrates continuous discovery of servers, services, service dependencies, switch connections, and lots of other things into the monitoring process. The discovery is "stealthy" and will never set off any network security alarms. Adding servers doesn't measurably increase monitoring load, and the system is expected to easily scale into the 100K server range. The discovery work is distributed among all the nanoprobes (agents), which run scripts that spit out JSON. The central system (CMA) stores these strings and runs optional plugins to create graph nodes.
vcprompt prints a short string, to be included in your shell prompt, with barebones information about the current working directory for various version control systems. It is designed to be small and lightweight rather than comprehensive. It has varying degrees of recognition for Mercurial, Git, Subversion, CVS, and Fossil working copies.
rgxg (ReGular eXpression Generator) is a C library and a command-line tool that generate (extended) regular expressions. It can be useful for generating expressions that match, for example, a specific number range (e.g. 0 to 31 or 00 to FF) or all addresses in a CIDR block (e.g. 192.168.0.0/24 or 2001:db8:aaaa::/64).
LMDB is an ultra-fast, ultra-compact key-value data store developed by Symas for the OpenLDAP Project. It uses memory-mapped files, so it has the read performance of a pure in-memory database while still offering the persistence of standard disk-based databases, and is only limited to the size of the virtual address space (it is not limited to the size of physical RAM).