NetGuest was the very first web application I made. It was a simple guestbook that allowed users to post short comments to a website. An administrative backend allowed the webmaster to view and moderate posts.
Written in Visual Basic.NET, the first version was very rough. The database code was very inefficient and it required Microsoft SQL Server to be installed on the server. It also required dbcreator permissions on SQL Server to install its own database.
The new version uses C#.NET and implements proper class encapsulation, master pages, and an ADO.NET Entity Data Model. The posts feed uses lazy loading of posts which means that only some posts are loaded as the user scrolls down. This speeds up the posts feed substantially as it doesn't have to load all the posts at once.