What add ons or modifications are a must?

Depends on what you want from your website. A forum or more than that? Xenforo is a great forum script but if you want to showcase your content in the form of an article, you definitely need a modification! 

I'd say the most basic and must is anti spam features, to keep people from filling your board with junk.

Layers of anti-spam are without a doubt a necessity. Spambots can dump thousands of spam topics on a site in under an hour if left unchecked. So having just one method is not enough. Things like:

• registration questions (that aren't the default ones),
• time checks (since bots can fill out all fields and "register" in like a few seconds, way faster than a human can so if the registration happens too quick it'd get denied),
• hidden anti-bot fields (so if stuff gets added there you know a human couldn't have registered),
• blocked countries (this might be a bit more controversial... but the ability to block high spam countries. For example... China is one of the leading spam producers, yet due to their heavily filtered/restricted internet you're unlikely to ever get an actual legitimate Chinese user so it's pretty safe to block China and reduce spam that way without affecting legitimate users. Anyone in China trying to access out will be using a VPN so they wouldn't appear like they're from China anyway.)

Beyond that it's a good idea to have an alerts mod (if one isn't standard in the forum software) so people know when they've been quoted/replied to or whatnot.

After that it really comes down to individual preference and what would work best for your board. I mean a board dedicated to music talk isn't going to need a mod that lets users log in with their steam ID... But a gaming forum might want that.  

Depends on the forum software you are using and what it is lacking in the core. I think a CMS of some sort is a must depending where you want to take your website!

I think if China ranks in top spamming countries but both South and North Korea do not leg behind by much. There are few other Asian countries in this list banned for participation by my reputed sites but is there a way you can really stop their participation?

Posted by: VirusZero

Layers of anti-spam are without a doubt a necessity. Spambots can dump thousands of spam topics on a site in under an hour if left unchecked. So having just one method is not enough. Things like:

• registration questions (that aren't the default ones),
• time checks (since bots can fill out all fields and "register" in like a few seconds, way faster than a human can so if the registration happens too quick it'd get denied),
• hidden anti-bot fields (so if stuff gets added there you know a human couldn't have registered),
• blocked countries (this might be a bit more controversial... but the ability to block high spam countries. For example... China is one of the leading spam producers, yet due to their heavily filtered/restricted internet you're unlikely to ever get an actual legitimate Chinese user so it's pretty safe to block China and reduce spam that way without affecting legitimate users. Anyone in China trying to access out will be using a VPN so they wouldn't appear like they're from China anyway.)

Beyond that it's a good idea to have an alerts mod (if one isn't standard in the forum software) so people know when they've been quoted/replied to or whatnot.

 

After that it really comes down to individual preference and what would work best for your board. I mean a board dedicated to music talk isn't going to need a mod that lets users log in with their steam ID... But a gaming forum might want that.  

That hidden anti-bot field sounds interesting!! Is it available for vBulletin do you know?

I don't think there's any such thing as a "must" add-on / modification for a forum, and I feel like I'm in a pretty good position to judge.. 🙃 

I've seen perfectly healthy and active communities just using the stock software.