The EAGLE Light Edition can be used for free!
Limitations:

1.The useable board area is limited to 100 x 80 mm (4 x 3.2 inches).
2. Only two signal layers can be used (Top and Bottom).
3. The schematic editor can only create one sheet.
Apart from these three limitiations the EAGLE Light Edition can do anything the Professional Edition can do. You can even load, view and print drawings that exceed these limits!