Top 20 NuGet attributes Packages

AngleSharp is the ultimate angle brackets parser library. It parses HTML5, CSS3, and XML to construct a DOM based on the official W3C specification.
MrAdvice allows to weave aspects at build-time (just like PostSharp, but free as in free beer). Write your own aspects in the form of attributes and apply them to target methods or properties. This version does not require any dependency (on the opposite of MrAdvice.Fody which requires Fody).
Creates and inject attributes and properties to existing types in runtime
Superset of MEF attributes. In addition to Export/Import contains attributes to support modern IOC (DryIoc) features.
Route messages based on Routing Attributes. Includes attributes for Exchange, Queue and Routing.
Super-set of MEF attributes. In addition to Export/Import contains attributes to support modern IOC (DryIoc) features.
Extensions for configuring Autofac with attributes
Attributes for configuring Autofac registrations
Attribute based mapping for NHibernate.
You can use attributes in the JetBrains.Annotations namespace to annotate your own code to make ReSharper analyze it with greater accuracy and insight.
Contains various basic file functions, functions for working with streams and working with CSV's.
CompilerAttributes
Advanced implementation of the Authentication filter and Authorization attribute for WebApi utilization.
Obsolete! Use https://www.nuget.org/packages/MrAdvice/ instead! MrAdvice allows to weave aspects at build-time (just like PostSharp, but free as in free beer). Write your own aspects in the form of attributes and apply them to target methods or properties.
Autofac extension that allows to automatically bind a type with configuration provider through attributes.
Configure messages and topology with attributes.
Extend objects with attributes at runtime.
Package Description
Common functionality for .Net applications - auditing for Entity Framework, generic repository interface, helper methods for working with attributes.
Bus Client that is API compatible with 1.x.