Whatfiles is a Linux utility that logs what files another program reads/writes/creates/deletes on your system. It traces any new processes and threads that are created by the targeted process as well.
Rationale:

I've long been frustrated at the lack of a simple utility to see which files a process touches from main() to exit. Whether you don't trust a software vendor or are concerned about malware, it's important to be able to know what a program or installer does to your system. lsof only observes a moment in time and strace is large and somewhat complicated.