Camlex.NET
Camlex.NET simplifies creating of CAML queries for Windows SharePoint Services by using expression trees.
Template Hub for SharePoint
The SharePoint Template Hub makes it possible for you to have a centralized repository for your templates. It solves the issue with one-to-one relationships between Content Types and Templates by splitting this up, and give you the possibility to reuse a content type for several templates without any implications. All templates can also have metadata connected to them that will come over to the document when it is saved in the target document library.
The document template repository is a standard SharePoint Document Library, thus it supports all the standard metadata, publishing and workflow features for working with your document templates, just like you would expect with regular documents.
SharePoint Property Bag Settings 2013
SharePoint Property Bag offers developers to store configurations settings at different levels of the SharePoint hierarchy outside of the application itself.