P.S. Irrelevant now, after some deliberation I decided to switch my engine to MPL2 (which automatically includes GPL/LGPL).

The comment in the code points to http://www.gnu.org/copyleft/lesser.html , which auto-redirects to http://www.gnu.org/licenses/lgpl-3.0.html these days.

With no mentions of version in the comment, does that mean Imaging now requires LGPL v3 ?
In that case it is impossible to use together with code that requires LGPL v2 (as included with the FPC RTL: the RTL does not mention version either but it refers to file COPYING which is a whole text of LGPL v2.1 included with the sources, which have no mention of other versions)

I am building my game engine around LGPL v2, not v3 as I borrow some minor pieces of code from the FPC RTL and also use Linus Torvalds' opinion as a guideline.

Stallman is a bad person to cause such schism.

P.S. If it's v3 I'd prefer to find a way to switch to it because Imaging is so good and irreplaceable. Helps a lot when using GLES @ Raspberry Pi where you need to feed the GAPI an exact texture format it needs.

P.P.S. I kept using 0.26.4 until year 2020 patching it manually (for x86_64 support, for example) because I missed this place and was looking for updates at the sourceforge page. Very funny in hindsight.