Avalanche is a network composed of multiple blockchains. Each blockchain is an instance of a Virtual Machine (VM), much like an object in an object-oriented language is an instance of a class. That is, the VM defines the behavior of the blockchain.
TimestampVM defines a blockchain that is a timestamp server. Each block in the blockchain contains the timestamp when it was created along with a 32-byte piece of data (payload). Each block’s timestamp is after its parent’s timestamp. This VM demonstrates capabilities of custom VMs and custom blockchains. For more information, see: Create a Virtual Machine
TimestampVM is served over RPC with go-plugin.