The info bar contains the popup-button for setting the desired Markup-language.
The following Markup-languages can be set in Textbundle Editor: Markdown, MarkdownExtra, MultiMarkdown, Textile, Wikitext, HTML, BBECode and Smark.
The setting made is automatically saved by Textbundle Editor and automatically preselected in the next newly created file.
The first time Textbundle Editor is launched the Markup-language Markdown is preselected.