Guild Craft is setup to show you what people in the guild can make / craft. With Patch 3.0+ by blizzard and the introduction of some new toys, Guild Craft's internal guts have been reworked. On load it will scan your tradeskills, and send em out in the new Blizzard style compressed format. Other members of the guild also running the addon will pick up on it and have your data.
If you upgrading from previous versions, your database will be automatically reset, as the database versions are not compatible. Also there is no more need to open your crafting windows or select what items to share.

To see what you've sent out to the guild and what they have, just bring up the Browser (/gcb or Left Click on the LDB Display of Choice)
The Browser has a basic layout, a drop down at the top left to show the available stuff, and a listing on the left pane of the craftables. The Crafting Tool tip is listed to the right. You can shift click the item in the left hand list to link an item into an open chat box or into the first chat frame. A search box is available to the top middle, this will search name and tooltip text of each item for the tradeskill. So if your under inscription and you search fro "rogue" all the rogue glyphs show up in the list.

Due to the change in the underlying methods and the new toys that Blizzard has provided, these lists now include everything by default excluding BoP items and "non-Craftable" items that are part of the tradeskill.

~~As Always, Problems, Bugs, Errors
http://wow.curseforge.com/projects/guildcraft/create-ticket/
*****DO NOT POST ERRORS OR BUGS IN COMMENTS SECTIONS OF WEBSITES
*****REPORT THE PROBLEM ONCE AND IN ONLY ONE LOCATION, the ticket Tracker

Other Minor Changes:
-Guild Management functions have all been removed, they weren't really used
-The Browser is now LoD and is a separate addon that comes packaged with Guild Craft.
-Added Colorization to crafter names, online, off line and not in guild.
-3rd Party Pull: In the Database Functions section you can pull other people's data from someone else.
-Purge - added method to purge people from the database.
-Browser~ Refresh button added, shift click to reload the entire cache.
-Fubar Support dropped in favor of LDB, functionality remains the same tho.

v3.1.9 ~ Offline Synch has been disabled for now, till i can figure out how to do it better. Live Scan of people with out the addon into the database has been removed also. It was buggie

**Known Bugs?:
There appears to be a change in the link system that has messed up the browser in some cases. Reseting your Database via the Options interface has appeared to clear this up. I don't know what they changed as i have not experienced this myself. If you do find it please email me your wtf file before deleting or reseting it please.