All the regular features of forums:

• Reply-to-user or reply-to-thread posting.
• Subscribe to topics, or just mark High Interest
• E-mail notification of post replies to you.
• Complete PM (Private Message) system.
• File Attachments.
• Flexible searching system.
• Optional guest access.
• Optional stats to show active users, total posts, etc.
• Ignore folders and topics you don't wish to read.
• Multiple forum system, with a single userbase and per-forum options.

Accessibility support:

• Easy-to-use frame-based layout.
• Multiple style options, including dyslexia support.
• I18N multiple language support, allowing a variety of languages to be used.

Various features unique to Beehive:

• Powerful HTML posting, without security risks.
• Advanced word-filtering facility.
• Polls, including upto 20 options, anonymous voting or public ballots, and more.
• Word Filter with Perl-compatible Regular Expression parsing.
• Lite Version, for use with PDAs and some mobile phones.
• Links section, for a forum-wide favourites list.

Extendable user profiles:

• Allows any number of configurable fields.
• Users can opt-in to a 'Forthcoming Birthdays' list.

Flexible relationships system:

• Ability to ignore users posts, or signatures.
• Ability to define 'friends', and easily see their threads.
• Complete Ignore feature, for blocking a user out entirely.

Full, easy to use admin tools:

• List possible aliases for each user.
• Ban by user or IP address.
• Delete all posts by a user.
• Create sticky threads.
• Style-creator, to create new styles.
• Comprehensive user permissions.
• Folders can be made no-polls or polls only.
• Logs of all admin activities.
• Optional gzip encoding of output, to save bandwidth.

And a lot of other little handy features.