[Operators] XMPP server recommendations

[Kristian Rink]

Folks;

we're currently running an internal XMPP service based upon openfire 
wich works well but has a few drawbacks that don't seem to be 
addressable with this implementation.


Wish list, in our environment:

- Users do use 1:1 messaging as well as some conference channels 
(restricted / open but still internal).

- Our users run Windows, Linux, Android and iOS, with clients mostly 
being jitsi, pidgin, gajim and Conversations (on Android).

- Transfer of files (mostly screenshots and PDF docs) is frequently used 
yet works not quite reliable with openfire.

- History of chats (1:1 and group) should be availble synchronized 
across multiple devices (for users using desktop and mobile clients); 
this should include files included in a chat history too.

- The service should run on Linux on a machine that is tied to Windows 
AD using winbind.

- The service should be able to map Linux users to XMPP users and 
certain Linux user groups to XMPP user groups (openfire does have this 
concept of server-sided rosters but I'm not sure how far this is an XMPP 
standard feature). Not having to maintain a dedicated user base would 
greatly help.

So far I peeked into ejabberd and prosody and am looking for something 
to replace openfire. What are your experiences? Can you recommend either 
of these or maybe any other XMPP server I left out by now?

Any hints greatly appreciated. :)
Thanks,
Kristian