Complex sentence: SDAL is a proprietary map format developed by Navteq, which was released royalty free in the hope that it would become an industry standard for digital navigation maps, has not been very widely adopted by the industry.
Split into simpler sentences: SDAL is a proprietary map format published by Navteq, which released it royalty free in the hope that it would become an industry standard for digital navigation maps. The format has not been very widely adopted by the industry.