Loomes' Nested Set is a class that can be used to manage a tree of information stored in a database. It can perform several types of operations to manipulate a hierarchy of nodes that are stored in a database as table records. Currently, it can insert a root node, insert a node that is child of a given parent, delete a branch of nodes under a given node, delete a single node, rename a node, move nodes, check whether the root node exists, and retrieve the whole tree of nodes.
Crabgrass is social networking, group collaboration, and network organizing Web application. It consists of a solid suite of group collaboration tools such as private wikis, task lists, a file repository, and decision making tools. Work is currently being done on a large user interface overhaul, better social networking tools, blogs, and event calendars, as well as better support for collaboration and decision making among independent groups.