Ethereum software has come out with codes where if it is activated by the users , it brings in so many extra features as well as network developments.
New version of ethereum (Geth) v1.8.20 got released and establishes the hard fork of the Constantinople which is the initial platform version. This software is been widely used by the ethereum’s network participants.
Similarly Constantinople is progressing as scheduled. This block was initially proposed and established the stage for the forthcoming release. The live of Constantinople will be from 14th January to 18th January.
Rinkeby testnet would be activated to block 3,660,663 before this live. This Constantinople activation was planned in the November itself yet the testing process delayed the launch to sort out the bugs. This has planned to bring in many changes in the design as well as decided to streamline the overall code platform.
Source: Coindesk, Reddit