Glade (Gds, Lef And Def Editor) is a freeware IC layout editor capable of reading GDS2, OASIS, LEF and DEF. It's distributed under freeware license. Some features are;

• Fast, hardware accelerated OpenGL graphics;
• Import/Export GDS2, OASIS, DXF, LEF, DEF and Verilog;
• Import Cadence display.drf and techfiles directly;
• Edit and display hierarchy from 0 to an unlimited number of levels;
• Create instance, label, rectangle, path, polygon, via, pin commands with interactive display during enter;
• Layer select window for setting layer visibility/selectability, current layer, choosing layer colour and transparency, fill pattern, line style/width and setting layer names;
• ...and many others!