Universal Extractor is a powerful and well-known tool to extract files from hundreds of different archive types, installers or otherwise compressed files. It has been created and maintained by Jared Breland until he set it on hiatus after the release of version 1.6.1. Currently, there are several slightly updated modifications floating around, which consist mainly of helper binary updates. Additionally, some improved versions with auto-updaters, more supported file types and GUI redesigns exist. Sadly, these are scattered around the internet and no central and easy download packages are available. As a user you would have to search through many forums in a wide variety of languages to even find a link to the program.
Universal Extractor 2 is the most advanced inofficial modification around, aiming at the inclusion of many wanted features, improvement of current ones, ongoing support and a central open-source distribution. UniExtract 2 started as a simple modification disabling the always-on-top status box and ended with the addition of dozens of extractors to expand the range of supported file types. New - and unique amongst the available modifications - features like a scan-only mode to identify unknown file types using multiple scanning applications, the batch mode or the extraction of audio and video tracks from multimedia files make it stand out against these.
As a short overview here is a list of the core improvements: