something other than uimport.exe

For the last 16 years I have incorporated uimport in with my own coding to create user accounts and manage their access to servers. But it is limited to windows xp or earlier. I would like to use a different tool to do so. I have heard of ICE and LDIF as tools to do so. But have no Idea on how to use them and I am having hard time finding any details on how to set them up.
Could some one pleas help?

Thanks
Dave.