The precursor to Xic was the Kic layout editor, a very simple no-frills layout editor developed at Berkeley in the 1980's. In the late 1980s, the author needed a layout editor to support contract development and research efforts in superconductive electronics, and adopted Kic, run under something called a ``DOS extender'' (to support 32-bit applications) on an early and very expensive i386 computer. This required extensive modification to Kic, mostly to support the PC graphics. Kic is still available as free software on the Whiteley Research web site.
After Unix became available for 386/486 PCs in the form of the FreeBSD operating system, DOS and direct-write graphics became history. Xic became a separate program in late 1995, initially using the X-window system (Xt) user interface toolkit. Over the following years, Xic became a full-time development effort, and the extraction, DRC, and other subsystems were added. Although to this day faint similarities to Kic exist, internally the code has been replaced has been replaced by several iterations of more modern code, and the database and other systems were replaced with improved implementations.
Eventually, Xic underwent a complete rewrite into C++ (from C) to improve maintainability and organization. The GTK toolkit was adopted for the user interface.
Whiteley Research Inc. was founded in 1996 to market Xic, and the companion WRspice program. Since then, Xic has continued to develop, as new users brought forward new ideas and requirements.