I don't think BSON de-dupes the keys in the manner that JCOF does? But it has other nice properties. In a game I worked on we used a BSON library that didn't re

I don't think BSON de-dupes the keys in the manner that JCOF does? But it has other nice properties. In a game I worked on we used a BSON library that didn't really "parse" the data when you loaded a file; it just kept a pointer to the original binary data and let you perform queries against it. We used this to keep our memory footprint low; instead of loading BSON files we would memmap them (getting a pointer that can be used to read the data right off the disk) and passed that to the BSON library. Bang, we could map a 10MB file and it wouldn't use 10MB of system memory; it would just swap portions in and out as they were used. This has performance tradeoffs but for us (on mobile, where there is no swap space) the memory savings was worth it.