SPL Token v2.0.6

Features:

• Multisig: require a 1x1 pairing of M signers to M multisig keys
• Allows various accounts to be borrowed multiple times in token instructions, which generally enables Account and Mint accounts to serve as their own authority
• Standardized error-case ordering in instruction processing

SPL Token v2.0.3

Features:

• A Mint requires a mint authority on initialization, and tokens must be minted in separate instructions. Once unset, the mint authority can never be reset, fixing the supply
• Token accounts can be frozen and thawed, if a freeze authority is set in the Mint on initialization. Once unset, the freeze authority can never be reset.
• Token, Mint, and Multisig accounts are required to be rent-exempt, to ensure consistency in authorities and a valid supply (now reported in Mint)
• Non-native Accounts can now be closed by the account's close authority, if the token balance is zero
• SetAuthority instruction now supports easy reconfiguration of Mint or Token authorities

SPL Token v1.0.0

An ERC20-like Token program on the Solana blockchain

SPL Memo v1.0.0

A simple program that accepts a string of encoded characters and verifies that it parses.
Currently handles UTF-8.