The coolest enhanced memo edit control for Delphi 2009 to Delphi10.3 Rio. Native VCL component, in standard and data aware versions, with the following main features:

Automatic syntax highlighting: keywords, comments and custom syntaxing algorithms. You won't believe how simple it is to automatically and dynamically format your keywords!
Rich set of free accessory components : gutter with line numbers, printer component with preview capability, live spell checker that works with Addict Spell Check, Url highlighter, Html highlighter, ...
Mix any font style or background/foreground colors for parts of your text, and use two different fonts at your liking;
No limit on text length, even on old Windows versions (works on Windows 98 and up). Handle 100MB easily on minimal systems (more details here );
Plus much more: multi level Undo-Redo, drag and drop editing, text justification, colum block selection, various properties and methods to interact at run time with the text content ...