Complex sentence: File formats that can be imported vary from HAT to HAT, though they can include such formats as ASCII, HTML, OpenOffice Writer and Microsoft Word, and compiled Help formats such as Microsoft WinHelp and Microsoft Compressed HTML Help.
Split into simpler sentences: File formats that can be imported vary from HAT to HAT. Acceptable file formats can include ASCII, HTML, OpenOffice Writer and Microsoft Word, and compiled Help formats such as Microsoft WinHelp and Microsoft Compressed HTML Help.