To my knowledge they all enable smart contracts but do have slight differences between them.
Ethereum as we know has scalability issues but currently has the most traction out of any of the currencies listed. Tons of new projects are being proposed and developed on its blockchain so it still has a ton of upside even with its foreseeable issues.
EOS promises to solve Ethereum’s scalability issues and provide the capabilty for developers to build far more advanced applications on their blockchain. Also has massive upside but still a lot to prove in the coming weeks and months.
NEM may be the most appealing because it has the lowest transaction fees and and most efficient blockchain that was built from scratch.
Neo is probably second to Ethereum ( and #1 in China) as far as the traction it has picked up since it’s inception and allows smart contracts like all the other currencies although I am not 100% clear on the major features that distinguish it from the other currencies. Does anyone else know the major differences?
Overall I personally believe that all of these currencies would be worth allocating portions of your portfolio to because they present serious upside. Besides these I’m most bullish on OMG and POWR. I would highly recommend checking them out.