Choice of development platform for Client, Client-Server application?

Question

Delphi

Good afternoon, an interesting task appeared, writing software for an unimportant center, the concept of software includes the entire set of software, document management, various accounting systems for everything and everything, access systems for both staff and customers, where they did what they did, etc. work with hardware, printers, cash registers, card readers, etc.
Now they have a boxed workflow and other software, written in Delphi either 4 or 5 (years in 2003-2004), any minor change and finishing it for what is needed takes a lot of time, and the price is not sickly, software salesmen sit in capital, programmers are somewhere in another city, in general, the chain is very long.
Actually the question is, the server part, it seems to me, can be done with a bang on a bunch of Python (perhaps the ORM djanga will help + postgre as a database), but what about the client part, writing on the same Embarcadero Borland only fresh, I don’t really want to, there is experience in developing large applications under Adobe AIR, there is little experience in Qt So ... I
would like to get some kind of cross-platform client side, a tablet, a regular PC, maybe a phone
so that any form any window can be drawn by the designer, let's say so.
I will be glad to various councils, examples, links.
PS I'm also glad to learn something new, that's why this question was born.

Answer 1

And nothing that only document management systems are written by hundreds of people for thousands of man-hours.
The client part - you will not believe - the easiest way in - the web does not care, on what, anyhow it was correctly displayed in the employee's favorite (or corporate) browser.
And such an “all and all in one” combine is not only written specifically for each company - there is an engine with ready-made functionality, but it can sometimes take years to complete it for technical processes or processes and routes, and most often it is accompanied by more than one person, but a department or an entire department, depending on the size of the company.
1 You in the company from all departments need to formalize the requirements for functionality, routes for passing documents, and other those processes.
2. Look at ready-made modern workflow systems, what they offer, what functionality is already there, what you will need to add / change according to the requirements of the TOR that you wrote earlier in paragraph 1
3. Do not forget that tasks are not selected for tools , and tools are selected depending on the tasks.
PS - I saw a smart workflow system on Sharepoint from a friend in an international company, but a department of 80 people has been working on it inside the company for the second year. I don’t remember what was taken as a basis, but in six months about 40% of the basic components were rewritten there.

Answer 2

If suddenly you have development experience in c #, then I advise you to do the client part on it, especially since you need to be exclusive in the interface, and wpf will provide this

Answer 3

If this is purely a workflow, then I recommend looking at two open-source systems: Alfresco and Nuxeo. It may be faster and easier to adapt them to the needs of the customer than to write from scratch.
Typically, enterprise systems are written in Java or C#. The interface is best web based. This will ensure minimal problems with the implementation and maintenance of the client part (due to the fact that there will be no need to install and maintain separate software on client computers). If you are interested in creating a colorful, desktop-like web interface, then you can look at ExtJS.

Answer 4

Take the web, html5, now it can be wrapped in almost anything.
Or look at beautiful frameworks, such as ExtJS-web, it can be different ...