Xmldego provides XML parsing and/or transformation by binding callbacks to XML parsing events in the context of an XML element. While SAX, for example, calls your callbacks on every start tag, Xmldego will do so only for the child axis path you request. Xmldego is particularly useful when only smaller bits of a much larger XML file need to be processed, because only interest in the relevant bits need to be coded. In contrast to a DOM parser, much larger XML files can be processed, because the whole file is not loaded into memory.
Ackr is a very small subset of grep/ack/rak, for lazy developers. grep is a great tool, a very powerful tool, but often too powerful for simple needs. Ackr looks for a search string in all text files and in all subfolders from the working directory, is case insensitive, has no options, doesn't look into hidden folders/files, and displays the search term in a bold font.