-Very tiny: all that is required is a standalone app (although it does create INI files, which I'll discuss later.) It's only 400kb, so it's very tiny and lite.
-Portable: I'm not entirely sure, but I'm fairly sure that it is portable. It has its own INI files, so I don't think it would need to store information in the registry. But the nice thing is that it has the option of install. In the ZIP that you download it in is a program called "Install.exe," which you can run to install. But if you don't want to install it, you don't have to; just delete Install.exe and install.script, and run portably.
-Directories only: Unfortunately, you can only select folders to backup, and not individual files. However, there are.....
-Filters: There is a whitelist, meaning that you can choose to only copy with certain extensions. Unfortunately, you cannot do filenames, but you can add extensions to the list. You can also filter by "Only Copy files created after ____" so if you only want to copy files that were created in the last month, you can, down to the specified minute.
-Profiles: I should have mentioned this sooner. With FB Backup, you can have multiple profiles, like one for My Documents, one for Program Files, and etc. However, FB Backup is a little different than some backup programs in that every profile is saved to an INI, and you can only have one loaded at a time. That just means that you have to go to "File > Open" and open a profile, back it up, then do the same thing for the next profile.
-Incremental Backup: Has the ability to do an incremental backup, meaning only new or changed files will be copied, which saves time and resources.
But there are a few things that FB Backup does not have that other backups do have:
-No schedule: Unfortunately, FB Backup has no schedule, which may be fine for some people (like me), but for other people, they may want automated backups.
-No Compression: That's right, no compression at all. FB Backup can only backup files. Again, fine for some people, but most people (I think, at least) would like at least the option of compression.
There's so much backup software out there that it's all really about preference. If you're one who just wants to incrementally copy files every now and again, FB Backup is great.