Generate keys/addresses for all altcoins I'm looking for a library or method to generate addresses for as many of the most popular currencies/altcoins as possible. Is there a known library that supports this? Or do I need to use a specific client for each coin?

Thanks!
Here is my "quite big answer":
I've successfully used http://cryptolife.net/upwg/ which is stated to be "Open Source JavaScript Client-Side Universal Paper Wallet Generator".  

It doesn't generate wallet addresses by coinname, but instead by the leading character within the wallet address.  I get these from the block explorer for the coin, looking at top address.

http://www.universalwalletgenerator.net/ lets you do it by coin name.