MXC the is internal currency, it is used to convert mined coins into more suitable format. You are mining cryptonight based coins.
I cannot find MXC on other exchangers, is it tradebale somewhere?
Currently no, it is not published on exchanges. But we are planning to publish it once we finish Maxwell Blockchain and GUI for Maxwell Wallet on pc.
For now, MXC is used as an internal currency. 1 MXC = 0.0000001 BTC. You can withdraw directly to any Bitcoin wallet or transfer it to your Maxwell Wallet.
You should create a wallet in that system. Once your transferred MXC, you can withdraw it to bitcoin, perfect money, advanced cash and other available systems.
In few weeks it wil be possible to withdraw MXC into other alts like Doge or Litecoin.
In future, we are planning to add VISA and Mastercard support to Maxwell Wallet.