Primero sería interesante que aclararas qué es un archivo TPL, porque la extensión es usada por muchos softwares distintos para diferentes cosas:
Cita: - PHP template file format
- CakeWalk Audio template file
- Resident units library
- Harvard Graphics template file
- Page Express template
- tpl file icon.tpl - Ulead Photo Express template
- Apple Mac OS X Stickies stickie document file
- ArchiCAD project template
- Adobe Photoshop Tool preset file
- Access Workflow Designer file
- ACT! document template
- Arena Template source code file
- BestAddress HTML Editor template file
- Canvas template file
- DataCAD template file
- fKey Template Designer file
- MicroImages text template
- NoteTab template
- RapidForm collection file
- SignIQ template
- TextBridge template file
- Timeslips TSImport template file