I recently started working and came to know AdobeAcrobat DC which I really, really like as a tool to archive and send around information.
Especially loved that you could ...
Really liking the software I thought about buying it. Having a MacOS I sadly had to realize I could only get the Adobe Acrobat DC Pro, because the Standard is not available for my OS.
Now the real shock started. Looking at the price I either could pay 29,74 € a month on demand, or up front either 17,84*12= 214,08 € per year or 665,21 € ones. I was shocked and thought thats way to much for a software just moving data from one format to another!
Then I tried to research and test alternatives using this page and also Mac's own tools (Automater, Preview). Again I was shocked, either the UI was really bad or the features were not even close to Adobe DC.
That was the time I started to ask myself, are there patents protecting Adobe? Why is there no competition earning the name? For Windows their is at least Foxit and Nitro ... but for Mac?
Does somebody could help out, and state if the technology is really tough to reengineer or if there are patents protecting the format?
First and foremost, there is the ISO 32000 standard, and anyone is free to create a viewer which is compliant to that standard. In fact, this is kind of encouraged.
Why Acrobat? Well, Adobe has 25 years of experience and knowledge on how to create a PDF viewer. Adobe also has the necessary resources. And Adobe has the market power… which they do use.
Apple would have the resources to do something useful, but Apple gives a shit about PDF (that's obvious, considering Preview.app messing up certain PDF documents beyond all repair).
Update, added after comment by OP:
About the features mentioned in the OP… Most of these implementations by Adobe are well done, and kind of mature technology. However, there are other implementations out there, and anyone is free to do something following ISO 32000… In detail:
• Converting to PDF is, of course, a side effect of the PDF-creation library Adobe uses in their other applications (InDesign, Illustrator, PostScript, etc.). This library is considered to be top class, and therefore, using it does make a lot of sense…
• Combining… Again, it is the library Adobe developed (for their own and for licenceable use), which can very well read, understand and write PDF. For this feature, there are other good products out in the market.
• Compressing… Smart use of compression provides an optimum between file size and handling speed. Good use and implementation of the various compression schemes.
• Typewriter feature… A bit of a marketing gimmick; it is essenitally an "add Text" annotation. The sole advantage of a form filled with the typewriter tool over a hand-filled form is that the further is better readability. Forms should be fillable, and their data should be retrievable without human interference.
• Redaction… Indeed, Adobe made good progress on this. The industry standard for Redaction is, however, still a plug-in (or server application) for Acrobat (Pro); (Redax by Appligent is the product).
• OCR… Adobe did acquire and license some very good OCR tools; for certain kind of text, the leading third party tools are somewhat better, for others, Acrobat would be the choice.