Interesting to read a thread like this...
@Ñuño Martínez, sorry for not replying, I don't remember ever seeing your mail.

Anyway, I've tried get Tile Studio to compile in Lazarus many times over the years and always failed, until this time.

Now I got the tile editor working (almost) completely. The map editor however doesn't do much. There are some really strange things going on with the Canvas.Draw function with transparent bitmaps.

It took me quite a while to figure out that the behavior of TabControl.TabIndex and Form.Resize are different from Delphi in whether events are fired or not. I don't know if such things are bugs or maybe intentional choices.

Anyway, the newest source code is available on github: https://github.com/Wiering/Tile-Studio/tree/lazarus, maybe some of you lazarus experts immediately see what the issues are, any help would be appreciated!