Open Artwork System Interchange Standard (OASIS (TM)) is a specification for hierarchical integrated circuit mask layout data format for interchange between EDA software, IC mask writing tools and mask inspection tools.

The name is the trademark of SEMI. It is developed by SEMI for microelectronics/semiconductor industry as a replacement for GDSII format, the IC industry de facto standard for IC layout data exchange for more than two decades.

Like GDSII, OASIS (TM) is a hardware- and software-independent binary data format.

It delivers the following improvements over GDSII:

• Up to 10 times smaller file sizes
• Support of 64-bit arithmetics
• Richer data format for exchange of information between design and manufacturing stages.