What exactly causes binary file "gibberish"?

• Are the binary values of the file trying to be converted into ASCII?

Yes, that's exactly what's happening. Typically, the binary values of the file also include ASCII control characters that aren't printable, resulting in even more bizarre display in a typical text editor.

• Is it possible to convert the view to display raw binary values, i.e. to show the 1s and 0s that make up the file?

It depends on your editor. What you want is a "hex editor", rather than a normal text editor. This will show you the raw contents of the file (typically in hexadecimal rather than binary, since the zeros and ones would take up a lot of space and be harder to read).

• Finally, is there a way to determine what program will properly open a data file?

There is a Linux command-line program called "file" that will attempt to analyze the file (typically looking for common header patterns) and tell you what sort of file it is (for example text, or audio, or video, or XML, etc). I'm not sure if there is an equivalent program for Windows. Of course, the output of this program is just a guess, but it can be very useful when you don't know what the format of a file is.

Binary data is often very random. Encrypted data in particular, by definition. Each byte can be represented by one of 256 characters (leaving Unicode out of the equation). ASCII only covers 128 of these, and only 94 of these are actual printable characters. Outside the ASCII range, you have a number of international characters and strange symbols. There are certainly more than 128 of these, so one must specify a codepage to select a specific set of symbols.

Anyway, since binary files can be represented as a very random assortment of familiar and unfamiliar characters, the file will look like gibberish if you open it in an editor.

You could always open a file (binary or text file, there really is no difference) in a hex editor, and look at the raw binary data.

There is no way to tell which program created a specific file. In particular, if the program has encrypted its data, all hope is lost. Otherwise, it is often easy to recognize certain "signatures."