Newbie on docsetutil

[vanag]

Hi,

I downloaded cocoa.vim and I ws browsing through the scripts (I am not
expert). I noticed that it could be modified to contain the gnustep keywords,
but the most intriguing part was the fact that it mentions a tool docsetutil
for documentation. I searched a bit and I found that it is Apple only (maybe I
am mistken). Is there much a functionality for gnustep? what documentation
tool is used? Does it have the features of docsetutil? can it be used in the
similar manner? 

I am personally interested to improve the cocoa.vim for GNUStep,. Am I
duplicating work?

Thanks