Joomla 3 has been around for a long time. It is easy to forget how successful the series has become and how much it has evolved over the course of the minor versions.
As it approaches its final year as a mature, stable version of Joomla, it is about to enter its security support phase.
Joomla 4's now available, but if you're thinking about upgrading from Joomla 3.9, here's some important things to keep in mind before you click the Update button.
As documented in the announcement of Joomla 3.10 as well in a recent magazine article, Joomla 3.10 is a bridge between the Joomla 3.x series and 4.x. It will be initially released together with 4.0.0 and starting from there gets two years of official support.
Joomla! Community Magazine™