Could you give your impressions about PKP-GTK?

Your concern appears to be valid.  I looked at GTK for developing desktop apps several years ago, and found very little adoption of the technology.
http://en.wikipedia.org/wiki/PHP-GTK

Also, I know nothing about this, but it might be worth investigating:
http://en.wikipedia.org/wiki/WxPHP

If you can tell us a little more about the nature of the apps you're redeveloping we may be able to suggest some alternatives.

Hello Ray!

Good to interact with you again.

I was planning to convert Visual FoxPro apps to PHP desktop app.

But after reflect, maybe the solution is to install Apache/ PHP/ MySQL locally and use it like  a desktop app, actualizing local and remote DB(s) -just in case of internet fails, with a syncronization mechanism to make de DB(s) consistente one with other - if needed, something already done with VFP app(s).

Maybe that's the reason PHP desktop frameworks was so low adopted.

You might want to consider a cloud application using Rackspace or AWS.  There are a lot of benefits of professional hosting (mostly that you do not have to do all of it yourself) and they are very inexpensive.

You certainly can install your own server instance and run it on a desktop computer (I use MAMP when I'm teaching).  It's a workable solution, but you have to make allowances for backup, data sharing, etc.  If you don't need 100% concurrency of data, you can just make periodic updates to the central data base.

With regard to internet failures, I can tell you that in my part of the world, my scripts are about 1,000,000 X more likely to fail!  Internet service is pretty reliable here, even in a blizzard.  So I would be inclined to build this as a web app rather than a desktop app.

In my region we have a very reliable internet service too, in my case even out of the cloud - by option.

The scenario is a little more complex:

I can't expect people using the app(s) I'm distributing and would like to convert have internet connection at every work station or  in some cases mandatorily have internet connections since I intend to assist people without to much resources.

Since I'm using PHP to internet jobs I initially tought about PHP-GTK to optimize efforts and then, after realize it's a discontinued and not very adopted  technology tought if maybe a locally install PHP/ Apache/ MySQL could be a reasonably solution, as posted.

Even the ideal conditions is founded.

The app(s) I'm focusing to convert are used in physical shop to sell books f.e.  and issue fiscal tickets to the buyers (when actualizing data tables too), is it common to do this by making the data go to the "cloud" and return to the local printer? I've personally didn't see it  in physical shops, anywhere. Filling the itens of a physical sell using internet is something I've never saw too, and I don't know how is it convenient and doable...

It's something amazing:  the time for do that compared with a local app doing the same is closer, isn't it?

(Sorry to be so wordy)

It's not a matter of build the app(s) these exists and could be downloaded at my site
www.espiriplug.com.br - point of sale with inventory control and more are built - just to say about one of the apps.

And these are in production in some places. The issue is these were built in a discontinued language (Visual FoxPro) and maybe another language would be necessary to convert these app(s) hereafter - even it's a no urgent task.

Since I'm using PHP for net projects I tought maybe it could be in some manner  the convertion language (so I asked about PHP-GTK), optimizing efforts.

But after reading your last scrap PHP is not adequated  to do this job - so I need to search for another strategy - maybe Windows Forms (.net) is the more logic path that I'm avoiding since it could be a hard step.

Well, it would mean learning a new programming language, and there are always obstacles to overcome when you do that.  But as you say it's not an emergency.

You might post something in the ,NET Zone here and get some ASP opinions.

Ray

Good to count on your expertise another time!
Now I'm certain PHP is not the correct path in this specific job, anyway.
So I'm taking courage to go to .net Windows Forms strategy.

Thank you very much!

Thanks for the points and thanks for using EE.  My follow-on suggestion would be to go over to the .NET Zone and post a question about best learning resources for .NET and Windows Forms (and any other keywords that might be helpful).  You'll find some very good answers, I promise!

Best regards, ~Ray