Editing GDSII (section)

== History ==
GDS = Graphic Design System (see [GDS78])

Initially, GDSII was designed as a stream format used to control integrated circuit photomask plotting. Despite its limited set of features and low data density, it became the industry conventional stream format for transfer of IC layout data between design tools of different vendors, all of which operated with proprietary data formats.

It was originally developed by [[Calma]] for its layout design system, "Graphic Design System" ("GDS") and "GDSII".

GDSII files are usually the final output product of the IC design cycle and are handed over to IC foundries for [[Fabrication (semiconductor)|IC fabrication]]. GDSII files were originally written on [[magnetic tape]]. The final deadline for IC designers is still called [[tape-out]] for this reason.

Objects contained in a GDSII file are grouped by assigning numeric attributes to them including a "layer number", "datatype" or "texttype". While these attributes were designed to correspond to the "layers of material" used in manufacturing an integrated circuit, their meaning rapidly became more abstract to reflect the way that the [[Integrated circuit layout|physical layout]] is designed.

As of April 2008, many [[Electronic design automation|EDA]] software vendors have moved to the stream format [[Open Artwork System Interchange Standard|OASIS]], which replaced GDSII.<ref name="eetimes-oasis-08">[http://www.eetimes.com/design/eda-design/4018771/Going-from-GDSII-to-OASIS Going from GDSII to OASIS], Philippe Morey-Chaisemartin (Xyalis) // EETimes 8/4/2008</ref> For smaller designs, GDSII continues to be used today.