What libraries exist for bitcoin/altcoin transaction creation and wallet generation? I am interested in developing a cryptocurrency-supported website and am looking for libraries that support cryptocurrencies for preferably either node.js or python.

I think I can only post in the newbie forum still, so I am asking here. Thanks.

Reading through the altcoin postings, it seems a lot don't focus enough on community building. You can't really have a currency without people actively supporting it. One of the postings I saw was just an enumeration of the coin's stats and a download link. It must take a decent amount of work to create a new altcoin, but I think that's only the smaller part of the work involved in publishing an altcoin.