NetIRC2 is an easy-to-use .NET IRC client library. It supports all major features relevant to making a chat client or bot. It has full support for synchronization contexts. You can use it from a Windows Forms or WPF GUI thread and chat events will be automatically dispatched, allowing you to completely ignore multithreading. It uses byte arrays internally, so mixed encodings can be handled. The IrcClient class can even be used as a component in the Forms Designer. Because it speeds up connect times with some IRC servers, an Ident server is included as well.
CryptSharp provides a number of password crypt algorithms: BCrypt, MD5 (and Apache's htpasswd variant), PHPass (WordPress, phpBB, Drupal), SHA256, SHA512, and Traditional and Extended DES. It also includes Blowfish, SCrypt, and PBKDF2 for any HMAC (.NET's built-in PBKDF2 implementation supports only SHA-1). If you are looking to store passwords, odds are CryptSharp will have the algorithm you want.
ogEditor is a Web-based WYSIWYG HTML editor with a built-in file manager. It features a Tag Selector which lets you view and edit a tag's attributes and internal styles while working in the Design view of an HTML page. Tag Selector displays the entire chain of tags which apply to the current selection or to the cursor position. When any of the tags is selected, its corresponding element will be highlighted in the Design view, and the selected element's attributes and internal styles are also displayed and can be edited in the Property editor window.
Piglet is a tool for parsing and lexing text for the .NET framework. The purpose of Piglet is to provide an easy-to-use tool for parsing text which can be easily included in any .NET project as a single assembly. In contrast to most parser generators, Piglet provides a fluent interface which enables you to express your grammar in a syntax which is accessible for users with no prior experience of parser generators. Piglet generates efficient, type safe, and reentrant LALR(1) parsers at runtime, which saves you from having a pre-compile step to generate your parsing tables. It also includes a lexical scanner generator which can be used independently of the parser generator.