libpurple
* Fix 'make check' on OS X. (David Fang)
* Fix a quirk in purple_markup_html_to_xhtml that caused some messages to be improperly converted to XHTML.
* Set "controlling-mode" correctly when initializing a media session. Fixes receiving voice calls from Psi.
* When looking up DNS records, use the type of record returned by the server (instead of the type we asked for) to determine how to process the record.
* Fix an issue with parsing XML attributes that contain "<br>". See ChangeLog.API for more details.

General
* Correctly disable all missing dependencies when using the --disable-missing-dependencies option. (Gabriel Schulhof)

Gadu-Gadu
* Fix display of avatars after a server-side change. (Krzysztof Klinikowski)

AIM
* Allow setting and displaying icons between 1x1 and 100x100 pixels. Previously only icons between 48x48 and 50x50 were allowed.

MSN
* Fix CVE-2010-0277, a possible remote crash when parsing an incoming SLP message. (Discovered by Fabian Yamaguchi)
* File transfer requests will no longer cause a crash if you delete the file before the other side accepts.
* Received files will no longer hold an extra lock after completion, meaning they can be moved or deleted without complaints from your OS.
* Buddies who sign in from a second location will no longer cause an unnecessary chat window to open.
* Support setting an animated GIF as a buddy icon.
* Numerous code cleanups and memory savings.

MySpace
* Fix a leak and crash when retrieving buddy icons.

XMPP
* Less likely to send messages to a contact's idle/inactive resource. Previously, if a message was received from a specific resource, responses would be sent to that resource until either it went offline or a message is received from another resource. Now, messages are sent to the bare JID upon receipt of any presence change from the contact.
* Added support for the SCRAM-SHA-1 SASL mechanism. This is only available when built without Cyrus SASL support.
* When getting info on a domain-only (server) JID, show uptime (when given by the result of the "last query") and don't show status as offline.
* Fix getting info on your own JID.
* Wrap XHTML messages in

, as described in XEP-0071, for compatibility with some clients.
* Don't do an SRV lookup for a STUN server associated with the account if one is already set globally in prefs.
* Don't send custom smileys larger than the recommended maximum object size specified in the BoB XEP. This prevents a client from being disconnected by servers that dislike overly-large stanzas.
* Fix receiving messages without markup over an Openfire BOSH connection (forcibly put the stanzas in the jabber:client namespace).
* The default value for the file transfer proxies is automatically updated when an account connects, if it is still the old (broken) default (from 'proxy.jabber.org' to 'proxy.eu.jabber.org').
* Fix an issue where libpurple created duplicate buddies if the roster contains a buddy in two groups that differ only by case (e.g. "XMPP" and "xmpp") (or not at all).

Yahoo
* Don't send and tags. (Fartash Faghri)
* Support PingBox. PingBoxes will appear as pbx/PingBoxName. (Kartik Mohta)

Pidgin
* Fix CVE-2010-0423, a denial of service attack due to the parsing of large numbers of smileys. (Discovered by Antti Hayrynen)
* Correctly size conversation and status box entries when the interior-focus style property is diabled. (Gabriel Schulhof)
* Correctly handle a multiline text field being required in a request form. (Thanks to Florian Zeitz for finding this problem)
* Search friends by email-addresses in the buddy list. (Luoh Ren-Shan)
* Allow dropping an image on Custom Smiley window to add a new one.
* Prompt for confirmation when clearing a whiteboard (doodle) session. (Kartik Mohta)
* Use the "hand" cursor when hovering over usernames in chat history to indicate that the username is an actionable item.
* Double-clicking usernames in chat history will open an IM with that user.
* Put an icon on the "Filter" button in the debug window.
* Don't treat "/messages/like/this " as commands.
* Explicitly mark user interaction when inserting smilies from the toolbar so "Undo" correctly removes these smilies.
* Clicking "New" or "Saved" in the status selector menu while typing a status message no longer keeps the status entry area stuck in "typing" mode forever.
* Show tooltips for ellipsized conversation tabs. On older systems, tooltips will show for all tabs.
* The File Transfers and Debug Window windows are no longer created as dialogs. These windows should now have minimize buttons in many environments in which they were previously missing (including Windows).
* Smiley themes with Windows line endings no longer cause theme descriptions not to be displayed in the theme selector.

Finch
* Fix CVE-2010-0420, a possible remote crash when handling chat room buddy names.
* Rebindable 'move-first' and 'move-last' actions for tree widgets. So it is possible to jump to the first or last entry in the buddy list (and other such lists) by pressing home or end key (defaults) respectively.