Is there an EOL or a LTS version of Dolibarr

Currently, there is no reason to introduce end of life in a Dolibarr version.
With no extra cost of work, due to a good organization of sources and the good tools, the project is currently able to guarantee that you can install a very old version, use it, and migrate to the last recent one, event if you wait 10 years before making your migration (Yes, migration from version released 10 years ago are still possible and guaranteed and this does not cost one penny for that because Dolibarr is "upgradable by design").
Since now 15 years, Roadmap is clear and never failed : There is 1 major version every 6 month, so you can amortized your project to deploy an ERP on 10 years if you want, migration project will still be possible and be guaranteed once the version is amortized. This is a very big advantage of Dolibarr software.

A lot of project introduce end of life of version and manage Long Term Support version, but this is because they are not able to maintain all past branches.
But the capacity of GIT, of our Continuous Integration system and our migration system allows us to be able to provide a maintenance version (a branch in GIT) for any past released version. So the choice to reduce the version or support to a very limited number of versions depends more on the integrator or the partner that you hire as your maintainer or support, than on the project itself. Adding restriction and forcing users to upgrade may be a good choice if it cost us a lot to maintain old version, but the truth is that the cost of maintaining old versions is near 0. So each branch on Github is currently still opened. It is the contributions that the project received (so the real usage on real life) that decides if a branch is still live or not.
For end users this is better than forcing them to upgrades on a system on which they invested a lot to get the perfect processes and needs sometimes 4 or 5 to be amortized (for large project on medium or very large companies for example).

For this reason, there is no "LTS" version and no "End Of Life" version on Dolibarr (or if you prefer, any version is a LTS with and End Of Life that is when your infrastructure has reached its End of life).

Dolibarr ERP CRM is Open Source software. You can download, use and redistribute it at any time. You want to test the latest version ?