The Portable Document Format was created in the early 1990s by Adobe Systems, and remained proprietary format until it was released as an open standard in 2008. Since then, it is under control of an International Organization for Standardization Committee of volunteer industry experts. Adobe distributed its Adobe Reader (now Acrobat Reader) program free of charge from version 2.0 onwards, and continued supporting the original PDF, which eventually became the de facto standard for fixed-format electronic documents.