This is largely a bugfix and TX fee schedule release.
- Remove ‘generate coins’ option from GUI and remove 4-way miner. (miners use software from elsewhere now.)
- Add -port option for P2P port.
- Minimum TX fee reduced to 0.0005 BTC (Client will accept and relay the lowered fee. GUI application remains at 0.01 BTC until v0.3.23 though.)
- Bug fixes, source tree reorg and more.
Upgrading to the most recent version of the client is not mandatory. With 0.01 BTC being worth as much at $0.18 USD recently, many individuals have reverted to v0.3.20 which does not impose the minimum fee that was introduced with v0.3.21. That older version has issues which were fixed with the newer releases but for an individual the older version is suitable for use in transacting with others. The minimum transaction fee when using v0.3.23 will be an amount 1 / 20th of the amount that the most current version of the client requires. As such, it is likely that v0.3.23 will follow shortly.