| pwrep | Password Repository Data |
| pws | ProWorks Data |
| pww | Patternland Weave Simulator Data |
| pwx | PowerAgent Exported Workout |
| px | ETCBC Parsed Text Data |
| px | Paradox Primary Index File |
| px | PX Submission Summary Data |
| px3 | PhraseExpress Phrase Data |
| pxb | Pixelmator Brush File |
| pxc | Photodex ProShow Cache |
| pxc | PX-Edit Classification Data |
| pxd | PXLab Design |
| pxg | Pixelmator Gradient File |
| pxicon | CandyBar Icon |
| pxip | Pixelmator Image Preset |
| pxk | PX-Edit Data |
| pxls | Pixelmator Layer Style File |
| pxml | Pandora PXML Data |
| pxp | IGOR Pro Packed Experiment File |
| pxp | PhraseExpress Phrase Data |
| pxs | Pixelmator Shape File |
| pxt | IGOR Pro Packed Experiment Template File |
| pxz | PSALMO Compressed Data |
| py1 | Cognos Exported Binary Model Data |
| py2 | Cognos Exported Binary Model Data |
| py3 | Cognos Exported Binary Model Data |
| pyg | IBM Cognos Data |
| pyh | IBM Cognos Data |
| pyi | Cognos Model File |
| pyj | Cognos Model File |
| pyk | pyStk Output Data |
| pyr | SOCSIM Population Pyramid File |
| pyu | pyUpSet UpSet Data |
| pyui | PyUI Data |
| pz2 | Poser Pose Data |