The PDF Version is formatted in the truest form and is recommended for general viewing. As everyone knows, resume-writing is an art form. This version is also guaranteed to (barely) fit on a single page.
The RTF Version is meant for those that insist on Microsoft Office-readable/editable formats.
The HTML Version is for those that prefer not to view files outside their browsers when possible.
Future goals include compiling a longer "Curriculum Vitae" with everything I left out due to for-private-sector constraints.