Is the Sia-UI v0.3.3.1 still usable? Can I still make transactions with it?
Highly not recommended. A hardforking bug was discovered in the consensus code. Right now you are still okay using 0.3.3.1 but the hardfork could trigger at any time. I strongly recommend that everyone upgrade to 0.3.3.3
Any plans you guys are implementing a stratum compatible mining rpc ?
I'd like to add a pool. Octane uses the same algo, got a pool for that already.
Probably we are not going to be able to. Though, I realized earlier today that it should be pretty simple to make a mining pool for Sia that gives full control of the transaction pool to the actual miner (instead of the mining pool). The miner chooses which blocks to mine and which transactions to put in the blocks, while still being able to get paid for work every few minutes.
It does require all miners to run full nodes, but while Sia is small that's really not an issue.
In short: Sia should have a mining pool released in 0.4.0 (eta 5-8 weeks).
What's the total supply?
was there any presale?
http://explore.siacoin.com/Right now there are ~295k coins being created per block. Each block has a reward of 1 coin less than the previous block. The minimum block reward is 30k coins per block.
There was no presale but the devs did mine the first 100 blocks (~30M coins). At the current moment, the devs have a combined total of less than 40m coins.