Oracle Solaris is not much in the press anymore, but used
for critical systems around the world.
Solaris 11.4 was launched in 2018. Oracle provides updates/patches
every month. Every quarter (Feb,May,Aug,Nov) the update includes new features.
Oracle will provide this monthly updates till at least November 2037.
Documented in:
http://www.oracle.com/us/support/library/lifetime-support-hardware-301321.pdf
Oracle is working to make sure Solaris will run properly after 2037 for example
with changes in SRU72 delivered in August 2024. It would be no surprise
if the updates will continue after November 2037.
https://blogs.oracle.com/solaris/announcing-oracle-solaris-114-sru72
For developers a pretty current version (CBE) is available
for free to develop and test software.
Solaris CBE Download:
https://www.oracle.com/solaris/solaris11/downloads/solaris-downloads.html
Oracle even provides patches for the older releases Solaris 10
and Solaris 11.3. The last patches are expected by January 2027.
We highly recommend to migrate to Solaris 11.4 and we are
happy to support you with our very experiences engineers.
Oracle's Management and Monitoring tools (OpsCenter and VM Manager for SPARC)
reached End-Of-Life. No patches are provided anymore.
We at JomaSoft continue to enhance our VDCF management and monitoring tool
for Oracle Solaris and Linux
https://www.jomasoft.ch/vdcf/
If you don't have a SPARC server yourself, maybe the JomaSoft
SPARC cloud could be helpful for you.
https://www.jomasoft.ch/services/