What is the difference between Casper and Algorand?
Casper -- Proof of Stake-Based Finality System overlaying an existing proof of work blockchain
Algorand -- Byzantine Consensus Based Protocol and?
One key difference is software patents. As Charles Hoskinson points out here: https://epicenter.tv/episode/234/
I think he provides a good "meta view" of mining algorithms with a comparison to their system, Ouroboros, in that video. Per my understanding of him, the bottom line is that there is still a great deal of research underway and likely to continue for quite a while. In all the different Proof of Work/Stake systems, there remains to be a great deal to be proven in terms of transactions per second and global consensus syncrhonization time metrics. We'll see if EOS can really produce blocks at 500mS -- particularly with the repeal of net neutrality. At the end of the day, that is all that will probably really matter to the community.