Ok, thanks!
I try to compile the LIBUSB_Test project. I get:
...LIBUSB_Test//unitmain.pas:44: undefined reference to `libusb_init'
... etc.
I installed the libusb-static package which contains the file "libusb.a". I make a symlink libusb-1.0.a to that in /lib64, /usr/lib/, /usr/lib64.
Which path is missing in Lazarus?
(Fedora 16 Linux x86_64)
G.