What is a Proprietary File Format?
A proprietary file format is essentially a 'format' or means of presenting data of which the specification is not made public. Often protected by patent or copyright these proprietary file formats are closely guarded secrets of the organizations who create them, who make it as difficult as possible for their data formats to be replicated by others either legally by their competition or illegally by hackers and the like.
The main benefit of maintaining exclusive control of a proprietary file format comes in the form of being able to force your customer base to maintain brand loyalty. A word processor for example that saves your files in a format that may only be opened by that particular brand of word processing software (and future releases by the same company) heavily restricts their customers future choices, as customers who may have been thinking of trying a competing brand will be reluctant if it is uncompatable, and unable to operate with their saved documents, etc.
.IPA File Extensions
There are now literally thousands and thousands of applications or 'Apps' available at the Apple iStore for use with Apple communication and media devices, and as Apple now say themselves within their advertising "There's an App for Everything!"
.IPA file extensions are given to the proprietary file format utilized by Apple for applications for use with such devices as the 'iPod' and the 'iPhone'. The '.IPA' file extension stands for 'iPhone/iPod Touch Application' and is essentially a compressed data archive that is readable only by Apple devices.
What are .IPG File Extensions?
Essentially the same as the .IPA application files described above .IPG file extensions are associated with games playable only on Apple made devices, and specifically the iPod.
What are .ITHMB File Extensions?
And as with the previous two the .ITHMB file extension is a tag associated with the photo/picture format utilized by Apple iPod's, etc.
The Problems with Proprietary File Formats for Customers
The .ITHMB file extension detailed above demonstrates a real problem for users of devices such as those produced by Apple when the shelf-life of the purchased device has come to an end. The internet is in fact littered with those seeking means through which to be able to open or convert .ITHMB file extensions and the like, unable as they are to gain access to their own photographs and files.
So whilst there are tools available for a price that are able to open and convert .ITHMB, .IPA, AND .IPG file extensions, this is often not an easy task. So with their own data seemingly held hostage, the customer usually is left with no choice but to purchase another device made by the same manufacturer, ad infintum.