Basically, I would like to run multiple separate versions of bitcoind on the same device. The reason for this is that I need the wallets to connect to separate programs via rpc (armory, counterpartyd and potentially the new mastercoin wallet). The problem I had is that to do this, I have to change the rpc username/password in the bitcoin.conf file so that it is compatible with each of these programs. I can't make one version of bitcoind compatible with all of these programs together. I was advised to download different versions of bitcoind, is this possible to do on one computer? If so, how? Thanks.