The principle behind T.OS is the establishment of a commercial payment system that utilizes digital currency. This will be the first such system in the history of the world. The solution comprises two coins. The TOS coin, or TOSC, is a regular cryptocurrency coin, which is not used for commerce, but can be exchanged on regular exchanges to any other digital currency. Its value may appreciate or depreciate and that is why it can't be used for commerce.
Viacoin is a Script-based cryptocurrency derived from Bitcoin. Similar to Bitcoin and other cryptocurrencies, Viacoin is also an open-source project. Viacoin aims to be the cryptocurrency of future, by integrating many innovative key technologies such as SegWit, APoW, Lightning Network, Dark Gravity Wave, and more. Viacoin claims to allow 25 times faster transactions than Bitcoin. It can be merged mined with the other Script cryptocurrencies like Litecoin, This is done by using an Auxiliary Proof-of-Work (AuxPoW) algorithm. Every six months, Viacoin halves the block reward that is given to users for Viacoin mining, resulting in a low inflation rate of Viacoin. Check out CoinBureau for the complete review of Viacoin.