Especially for enterprise uses, there are a bunch of things that are only implemented in Adobe Reader, especially when it comes to forms, interactive elements, workflow etc.
PDF is only open in the sense that .docx and other MS Office formats are open - there is a spec, and you are allowed to implement it, but it is almost impossible to implement 100% of the features. Programs like Evince (Poppler) and Sumatra have come a long way. They are really excellent and read 95% of PDFs, many even faster and with less RAM usage than Adobe, and almost 100% of static PDFs ("print to PDF").
But for the occasional PDF form, if I don't want to print it and fill it out by hand, I have to use Adobe (Poppler sometimes gets the font size wrong so you don't see when you are overflowing a field, code that checks whether you filled it out correctly doesn't work, and highlighting that tells you which fields are for what kind of user to fill out is also often messed up).
Actually what I just do is to run Adobe Acrobat Pro in wine, which allows me to actually save arbitrary filled out forms.
Finally, one ironic benefit of the Adobe Reader is that it is distributed in binary form. If you are stuck on a Linux distribution a few versions back, you can just download and extract it to your home directory and run it from there. I realize that from-source or package manager purists might cringe at that thought, but it actually saved me a couple of times when I just had to print out a stubborn PDF (and couldn't ask the admin to kindly update my distribution at work...).
"there are a bunch of things that are only implemented in Adobe Reader"
this is actually accurate (for ex how many know that the reader has a Javascript execution engine integrated into it?) - when people say that there are other free 'alternatives' anyway, most miss out on this fact. Like you mentioned, good alternatives cover 95% of the use-cases, so almost no one discovers this by hitting a wall.
does it support digital signatures (i.e. from a Smart Card) within forms like Acrobat does? This seems to be required for a lot of PDF forms I've had to fill out in the past few years.
Yeah, not exactly sad about this one. PDF being an open spec, the closed source acrobat reader is completely irrelevant to the Linux world (if not entirely harmful to newcomers to linux who go and find the only PDF reader they ever knew about).
Isn't this type of attitude what holds Linux back from being a viable desktop OS? Average consumers would want popular apps that they know. How is that harmful?
Just because Linux is open source, doesn't mean every app on it has to be. It needs popular apps to ever be a real desktop OS. No different than why Windows phone OS struggles today.
> Just because Linux is open source, doesn't mean every app on it has to be
No, but every app being open source (or rather Free Software, which is usually the case) can be supported easily by communities of users who can then bring it to tons of different architectures. That's why you get Evince on ARM, for example, and not the official Adobe Acrobat Reader.
But on the other hand, every app is just as free to be disregarded by a community of developers even if there is still lots of end users who need it. Or for the software to never reach the level required by intense professional use. Or a understaffed and underfunded community that provides a critical but unsexy part of the infrastructure coughheartbleedcough.
this is true, but if you are going enterprise-grade you at least will sign an x-years support contract. If there are lots of end users for desktop software then it should in theory be profitable for a company to keep making it, rather than being dependent on volunteers to stay interested.
>If there are lots of end users for desktop software then it should in theory be profitable for a company to keep making it,
I've been bitten this way too. It was a hardware/software product, small company made a neat little USB DAQ that became very popular. Bigger entrenched player bought the company and discontinued the line. Shortly after that they released their own product based on the ones they discontinued, but now it requires a much more expensive software package. Just because a commercial product is profitable does not guarantee its longevity.
every app being open source (or rather Free Software, which is usually the case)
Virtually every open source application is also Free Software, and vice-versa. The most common licenses (GPL, BSD, MIT, Apache, etc) fit both definitions.
I have seen "Open Source" licenses which do not permit modification nor re-distribution. It's certainly not equivalent to the principle of Free Software.
Ah, yes, there are "open source" licenses that don't follow the Open Source Initiative's definition. Still, Linux distributions tend to abide by it, as far as I know.
How GNU/Linux is relevant here? Average consumers know Windows and would want it (seriously, they frequently consider GNU/Linux to be another version of Windows and expect it to behave almost exactly like Windows did, then get disappointed it doesn't - that happened to my dad, for example)
GNU's not Windows, nor strives to be one. It's about bringing Free Software to whoever wants/needs it, not winning in popularity contest.
I don't care about Adobe Acrobat being closed source (though an open source one would be better). I care about it being a terrible app.
There's a lot of linux-compatible closed source apps I enjoy. Teamspeak, games, etc. Adobe Acrobat is one of the ones we absolutely don't need - there are many better alternative.
I still use it to fill out PDF files with forms. What other linux PDF viewer can do that? I heard that KDE/Okular can do it, is there any KDE independent software that can do it?
UK government use some PDF forms that use Acrobats digital signatures and won't work properly on anything else I've tried. Don't know why they didn't create them as web forms/apps in the first place however.
What PDF readers on linux are 'best recommended'? I compared acroread with evince and kpdf in the past and found that acroread was the most parsimonious in use of resources (especially RAM on large documents). Have not repeated the comparison recently, so will be glad to hear about recommendations with more recent experiences with large documents with images.
Personally, i prefer "zathura". besides filling out forms it can do everything, with a very sleek ui and outstanding keybindings (vim-esque). I encourage you to try it :)
Just some general info: Evince and Okular (the successor to kpdf) both use poppler under the hood (which is maintained/released by the Okular maintainer), so their performance and behavior will be somewhat similar, though you can make a difference at the app level with things like tiled rendering and smarter prefetching. I'm not on top of how the two compare there, though. Okular also has pluggable backends and there's an in-development mupdf backend around.
Firefox's builtin pdf.js reader has really matured and I switched to using it as my primary reader. It's even good enough for me to read books since it remembers the location I'm on, even if the browser process dies horribly.
I also use Okular. It has recently gotten support for keeping multiple documents in tabs rather than separate windows. However, I find it to be slow when searching big documents and slow to render large graphics in a page.
I absolutely dislike the pdf viewer in Chrome. It fails at even the basic things a pdf reader should support. E.g., it lacks a concept of pages. You can't jump to a certain page. You can't even know the total number of pages. It doesn't support the pdf's TOC. For any pdf which contains more than one page it is therefore useless. I can't understand how the Google folks ever thought this was a good idea.
I prefer Okular or Evince for Desktop viewing and pdf.js for in browser viewing. pdf.js is a bit slow when loading the pdf. But the user interface is quite nice in my opinion.
On the other hand its one of the (or the? at least last I checked) only pdf readers on Linux which supports subpixel rendering of text and other vector content, which makes documents much more easily readable in my opinion.
Unfortunately I have to correct page proofs of papers back from scientific publishers using Adobe Reader. This is going to make things tricky unless I have a WIndows machine.
