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Tim Walters .NET Blog:
Application Blocks for faster coding

this is an older message .
here's some links:
Microsoft patterns and practices for Application Architecture and Design (the main page)
Smart Client Offline
Asynchronous Invocation
Caching
Configuration Management
Data Acces - NOTE: has been updated to version 3, GotDotNet Workspace for DAABAF (supports Abstract Framework)
Exception Management, there are two:
Exception Management (basic exception management)
Enterprise Instrumentation Framework (advanced exception tracking, logging, performance counters etc)
Logging Application Block (based on the EIF)
Updater (can auto-download and install updates to your application)
Some of the Application Blocks that aren't as applicable for me, but here for reference:
Authorization and Profile
Aggregation
User Interface Process
Quite a few great bits of code there.
PS: I will be posting an update to my Heirarchial XML into SQL article, as well as it's companion article (SQL->XML), hopefully later this week"