The dataset file extensions used by the Roper Center

.por — SPSS portable data file
.sav — SPSS data file
.sps — SPSS system file
.dat — ASCII data file (Bring into SPSS, Stata)
.do — Stata command file
.dct — Stata dictionary file
.dta — Stata system file
.vxref — Variable Cross-Reference file
.zip — Zip file