FileInfo.com - The File Extensions Resource

.$DB File Extension

File Type	dBASE Temporary File
File Format	File
Common?	No
File Description	Temporary database file created while working on a dBASE database; may be used to recover changes made to a database if dBASE unexpectedly quits
Program(s) that open $db files	Windows: dBASE

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/$db