Reference implementation of getblocktemplate?

I'm searching for a sample miner in Python, C, Verilog, or any other language that works as a solo miner. It should take a getblocktemplate JSON from my local bitcoind and then submit the discovered nonce back to bitcoind core on the testnet. What I'm really interested in is how to pull data from the getblocktemplate and send it to the SHA256 hasher, plus how to embed the found nonce and pass it back to bitcoind. I get the hashing part but I'm not too familiar with the terminology in the BIPs, so looking through some code might help me figure things out. This is all about understanding the process better, not for making money.