Nodes - Historical data about detected full nodes.
Mempool - Historical data on full node mempool size.
Propagation - Comparisons of block and vote propagation times on the network.
PoW - Proof of Work mining pool data.
VSPs - Voting Service Provider data.
Exchanges - Historical exchange rate information.
Community - Historical data points for twitter, reddit, github, etc.
Stats - DB stats about dcrextdata.