Despite their beneficial influence on interoperability and markets, problems of detrimental opportunism occur with technology standards, including standards implemented in software, which this Article calls "Software Standards." inspired by new perspectives on the study of semicommons in the history of real property, this Article Contemplates the substitutability of free and open source software ("FOSS") for traditional standard-setting approaches. Standards are analogous to semicommons, where public and private use interact, raising the possibility of opportunistic influence on the Software Standard to increase private gain at the expense of the public benefit in a more uniform standard. With its source code disclosure requirement, FOSS shifts and dampens this opportunism, although various limits influence the reach of its effect. The political economy around a standard will express itself differently under a FOSS implementation, and clearing intellectual property rights in the standard is no more certain than under the traditional standard-setting approach.