As a big ASP.NET advocate, I'm loving the recent surge in open source / free ASP.NET applications that are hitting the web - And what's more because Microsoft have given us some great building foundations with the frameworks like the ASP.NET Membership Provider, a lot of these open source programs are very high quality!  More so than some of the paid applications.

I thought it would be a good idea to create an ever growing list of all the open source ASP.NET applications I could find - Obviously I haven't had chance to download or install every application so I can't vouch for them

e-Commerce / Online Shopping Carts

1. Dash Commerce - http://dashcommerce.org
2. Dot Shopping Cart - http://www.dotshoppingcart.com/
3. VevoCart - http://www.vevocart.com/
4. e-Shop ASP.NET - http://fkn1337.com/e-shop-aspnet-mysql-script/
5. PressTopia Shop - http://presstopia.com/dnn/Default.aspx?tabid=236
6. nopCommerce - http://nopcommerce.codeplex.com
7. MVC eCommerce Starter Kit - http://mvcecommercekit.codeplex.com 

Content Management Systems

1. Umbraco - http://umbraco.org
2. DotNetNuke - http://www.dotnetnuke.com
3. Sense/Net CMS - http://sensenet.codeplex.com
4. Novella - http://novella.codeplex.com
5. N2 CMS - http://n2.codeplex.com
6. MojoPortal - http://mojoportal.codeplex.com/
7. The Beer House - http://www.codeplex.com/Wiki/View.aspx?ProjectName=TheBeerHouse
8. My Web Pages Starter Kit - http://www.codeplex.com/MyWebPagesStarterKit/ 
9. Basic CMS - http://www.basic-cms.com
10. JMD CMS - http://www.codeplex.com/JMDCMS/
11. Nickel & Dime CMS - http://ndcms-net.sourceforge.net/
12. Nolior EZNews - http://sourceforge.net/projects/nolioreznews/
13. Hydrogen CMS - http://hydrogencms.codeplex.com

Blogs / Blogging

1. Blog Engine .NET - http://www.dotnetblogengine.net
2. BlogSVC (MVC) - http://www.codeplex.com/blogsvc
3. Oxite (MVC) - http://oxite.codeplex.com
4. DasBlog - http://www.dasblog.info
5. Sub Text - http://www.subtextproject.com
6. PressTopia - http://presstopia.com/dnn/Default.aspx?tabid=160 

Link Directories

1. (ASPLD) ASP.NET 3.5 Link Directory - http://www.n3o.co.uk/software/aspld.aspx
2. XD Link Directory - http://www.ex-designz.net/softwaredetail.asp?fid=835
3. ASP.NET 2.0 Link Directory - http://www.davemackey.net/Applications/LinkDirectory/tabid/88/Default.aspx

Customer Relationship Management (CRM)

1. Splendid CRM - http://www.splendidcrm.com

Wiki's

1. FlexWiki - http://www.flexwiki.com
2. ScrewTurn Wiki - http://www.screwturn.eu/Default.aspx?Page=Wiki&AspxAutoDetectCookieSupport=1 

Instant Message Apps

1. IM.NET - http://www.dotnetim.com

Forum / Portals / Networks

1. Kigg (Digg like application) - http://www.codeplex.com/Kigg
2. Club Starter Kit - http://www.codeplex.com/ClubStarterKit/
3. Drop Things (Web 2.0 Portal) - http://www.dropthings.com
4. Yet Another Forum - http://www.yetanotherforum.net
5. DMG Forum - http://www.dmgforums.com/

Recruitment / Job Systems

1. Job Site Starter Kit - http://www.binaryintellect.net/articles/a203c824-aec1-41b7-b3ec-49a15d5c9ebb.aspx
2. Stock / Inventory Tracker - http://itracker.df-software.com/download.aspx

Web / E Mail

1. DotNet Open Mail - http://dotnetopenmail.sourceforge.net/
2. qqMail - http://www.umailcampaign.com/mailcom.aspx
3. Sharp Web Mail - http://anmar.eu.org/projects/sharpwebmail/
4. Web News Letter - http://www.codeplex.com/newsletter 

Image & Video Galleries

1. Media Library Starter Kit - http://www.asp.net/downloads/starter-kits/media-library/
2. ASP.NET Foto Gallery - http://www.pentabyte.de/software/WebControls/
3. gPhotoNet - http://www.thezeal.com/software/index.php?gPhotoNet

Classifieds

1. Classifieds Starter Kit - http://msdn.microsoft.com/en-us/cc533489.aspx
2. Dating .NET - http://www20.brinkster.com/joemay7/

Help Desk/Ticketing Systems

1. Slick Ticket - http://slick-ticket.com

Misc

1. ASP.NET Small Business Web Site Starter Kit - http://msdn.microsoft.com/en-us/cc533514.aspx
2. ASP.NET Personal Web Site Starter Kit - http://msdn.microsoft.com/en-us/cc533486.aspx
3. Time Tracking Website - http://msdn.microsoft.com/en-us/cc533488.aspx
4. DinnerNow (Food Ordering System) - http://www.dinnernow.net
5. Bug Tracker .NET - http://ifdefined.com/bugtrackernet.html

If you would like your application added to this list please just post a link below and I'll add it