Firefox

Take WordPress for example. It is a predecessor of b2, which became dormant in the past. Netscape and its evolution towards Mozilla and Firefox resulted in what is arguably the best Web browser, among many browsers in existence. AbiWord, KOffice, OpenOffice and StarOffice share some common fundamental codebase and they all (if not most) are here to stay. This comes to show the power of looking upon the shoulders of others, constantly extending in this code-driven community.