[gravypod]

There is a different between prototype and project. If you're experimenting with features you're not making a project. If you're making a project (I hope) you're not experimenting with features. That should be done in a prototype.

[nickpsecurity]

There's overlap. Most FOSS or personal projects are prototypes for something built for fun or learning. Something can be a project without it needing success, money, or quality.

I believe Fred Brooks got famous pointing that out although it was unintentional for who he wrote about. ;)