Maybe it's for performance reasons. I have a web server in go that generate (big) png on the fly and most of the time is spent in the png encoding (mostly the c

Maybe it's for performance reasons. I have a web server in go that generate (big) png on the fly and most of the time is spent in the png encoding (mostly the compression). PNG encoding is a heavy task. Here's (from my blog) a pprof profile of my server : http://canop.org/pub/pprof4353.0.svg http://canop.org/pub/pprof4353.0.svg so that you can see the burden. (I didn't make comparisons with other languages so I don't know if Go's png encoder is fast or not, I suspect it isn't)