https://www.digitalcoinsexchange.com/blogs/bitcoin-core-0-12-1-released-and-ready-to-roll/ 15 April 2016. The day marked the official release of the latest version of Bitcoin Core, i.e Core 0.12.1 which is specially developed to provide block size scalability.

1.
Updates Rolling Out,” I underlined a few anticipated changes and enhancements in this
new version including the deployment of BIP9, 68 and 112 soft fork. But one thing that
was somehow missed out is the ​Block Size​ ​Scalability​. Yes, Bitcoin Core 0.12.1 is
giving a prime focus on the block size scalability by following the ​Capacity​ ​Increases
Roadmap ​which was discussed by the ​Core​ ​Team​ in December last year.
On 21st December 2015, the Bitcoin Core Team released an official statement that it’s
working on the capacity increase in the bitcoin system.
This step however, seemed obvious owing to the ongoing debate regarding the block
size of bitcoin.
Significant Changes
The new version of Bitcoin Core involves numerous notable changes. Many of these
changes have already been mentioned in my earlier blog post. But some things were
left out for sure.

2. Apart from the various BIP deployments and several bugfixes, the Bitcoin Core 0.12.1
forms a scalable network for bitcoin transactions powered by the blockchain based
Smart​ ​Contracts​. The Core 0.12.1 also owns the capacity for up to 29 parallel fork
deployments at the same time. This has been possible due to the BIP9 soft fork ​version
bits​. This enhanced soft fork deployment capacity will make it more susceptible to a
larger number of changes. And not only that, these changes will take place in a faster
and truly decentralized manner.
Upgrading And Downgrading
How To Upgrade?
● Before upgrading to the new version, make sure you have shut down the older
version if you have it installed in your computer.
● The older version takes a few minutes to shut down completely. So wait until the
process is completed.
● When you’re done with all this, run the new Bitcoin Core installer.
● It might take several minutes for the installation process to complete.
Downgrading To Pre­0.12 Versions
The upgradation process is quite simple but if you want to downgrade it to the previous
versions, it might be a bit hitchy. This is because the 0.12.0 and 0.12.1 are not
compatible with the pre­0.12 versions.
So if you want to downgrade to the previous versions after indexing with 0.12.0 or
0.12.1, you’d need to reindex when you first start with version 0.11 or earlier.

3. This new Core update seems better and promising and it might give goosebumps to the
developers of Bitcoin Classic. Now it will be interesting to see how the developers of
Bitcoin Classic react to this.