Library path

Q: Where do I add the path for source of 3rd party components? In Delphi it was in the "Library path".

A (forum user wp):

Lazarus is very different from Delphi regarding the path to 3rd party units.

3rd party units come to you in packages (extension .lpk). In order to use a 3rd party unit in a project you add the corresponding package to the requirements of the project: Open "Project" > "Project inspector". Click "Add" > "New requirement" and select the package from the list > "OK". Now the package appears in the lower part of the list in the project inspector ("Required packages"), and the IDE knows where to find the units contained in the package so that you can add any unit contained in the package to the uses clause.

If the 3rd-party component is "installed" (normally: if there is an icon in the component palette) simply drop the component on the form and the project is automatically extended by the related package (and the unit is added to the uses clause of the form).

Unless you really know what you are doing you should never extend the unit path ("Other unit files" in the project inspector) by the path to 3rd party components - it is easy to create lots of compilation issues if you do this.