It's a decentralized open source payment system which supports multiple currencies, including bitcoin, and which has no reliance on opencoin's presence to succeed - although they have done a huge amount of work on it.

decentralized: anybody can run or create a node, anybody can implement a node, anybody can add features to, modify, or improve a node, anybody can use any ripple node for the same purpose, all nodes share a distributed ledger (like blockchain)

open source: the source is open, readily modified by anybody, and freely available to anybody with interest, myself and 100 others at least have commit access at this time, it's being prepared for mass distribution and has been moved to it's public repo ready for launch when stable enough to ensure the millions of USD worth of currency it manages is 100% secure and unhackable.

XRP however, does has a controlled distribution from a central source, which is a for profit company. Don't confuse the two, it's a shame to write off such a great leap forward in payment and clearance systems just because one of the currencies it supports is distributed by the company that creates it - they do give masses of it away free though, and only sell comparatively small amounts of the currency in order to fund development of ripple.. when investment funds and companies like google aren't sponsoring the work that is.