HakuNeko - HakuNeko is an all-in-one cross-platform utility that supports you to download manga and anime with various website support.

RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.

Hitomi Downloader - Desktop application to download images/videos/music/text from Hitomi.la and other sites, and more.

Expresso - The award-winning Expresso editor is equally suitable as a teaching tool for the beginning user of regular expressions or as a full-featured development environment for the experienced programmer with an extensive knowledge of regular expressions.

HDoujin Downloader - A powerful doujin/manga downloader that supports hundreds of different websites.

rubular - A ruby based regular expression editor