EmbroideryShristi provides below popular embroidery design formats :
CSD, HUS, PES, EMB, DST, EXP, JEF, PEC, SEW, XXX, PCS, PCQ
Update:
Of course, the old design will be available in old file formats only, The above update is applicable to new designs only.
Note: You may find some designs in EMB native format only. It's always better to check the "DATA SHEET" section at the bottom of the page to see what are the formats available for specific design.
You could use to "Wilcom True sizer" to convert EMB to any other popular formats.