Text Editing

ActiveLedIt!
A UNICODE word processor rich text control. By Sophist Solutions.
http://www.sophists.com/Led/ActiveLedIt/

Chado Software
SpellText: a text box component that checks spelling as you type. SpellServer: spellchecking for your ASP web sites. SpellEditor: a full Rich Text box that checks spelling as you type.
http://www.chado-software.com/

Exontrol ExEdit
Add to application an easy-to-use edit control that supports built-in HTML format, and syntax highlighting as well. [Control, Commercial]
http://www.exontrol.com/exedit.jsp

Input Pro
Collection of formatted edit controls. By FarPoint Technologies Inc.
http://www.fpoint.com/products/input/input.aspx

Polar SpellChecker
Spell checking component that is bundled with 12 language dictionaries including English, German, French, Italian, Spanish, Dutch, Swedish, Danish, Latin, Slovenian, Czech, and Polish. By Polar.
http://www.polarsoftware.com/products/spellchecker/index.html

TachyonSpell
ActiveX spell-check component. Includes an English dictionary of 102,000 words, and uses "Fuzzy Logic" for its suggestion matching algorithm. [Commercial]
http://www.tachyon-labs.com/tachyonspell.aspx

TX Text Control
Provides word processing functionality in component form. By Imaging Source.
http://www.textcontrol.com/

UniToolbox
A set of Unicode-aware ActiveX controls and utilities for creating Unicode-enabled software. [Commercial]
http://www.unitoolbox.com/