How to determine what type of coins a wallet.dat contains? I have a number of wallets. Is it possible to detect the type of (alternative) coin it contains?
Here's one way I found.

Get pywallet (https://github.com/jackjack-jj/pywallet) and run

python pywallet.py --dumpwallet --wallet=/foo/bar/wallet.dat


Look in the output for a field called names.  This will contain a list of addresses in the coin's own format, and by looking at the first character you can try to identify the coin by its version byte.  See here for a list of some common ones.  For example, 1 is Bitcoin, L is Litecoin, etc.

Note that you will see a number of other fields named defaultkey, addr, etc.  These will appear to be in Bitcoin address format (starting with 1), no matter what the actual coin is.  The reason is that for these keys, the wallet.dat file only contains the private key, and pywallet has to do the conversion to the public key and address.  In  particular, pywallet has to fill in the version byte, and it always picks the Bitcoin version byte unless told otherwise on the command line.  So you always get a Bitcoin-style address in these fields, so for purposes of identifying the coin, you should ignore them.