FileInfo.net contains a search-able database of file extensions with detailed explanations of each file type. Every file extension entry contains information about the file format, a description of the file, and how to open the file. Programs for opening

Zotero [zoh-TAIR-oh] is a free, easy-to-use Firefox extension to help you collect, manage, and cite your research sources. It lives right where you do your work — in the web browser itself.

Mozilla’s Firefox browser claims to provide a safer browsing experience out of the box, but some of the best security features of Firefox are only available as extensions. Here’s a roundup of some of the more useful ones I’ve found.