Latest release of SMath has been issued more than one year ago, and it is clear that Andrey has not enough spare time to work on a continuous improve and release cycle for SMath. Please note that I totally understand Andrey position, SMath is a great piece of software engineering, and it reached in short period impressive capabilities, compared to what proprietary and well funded software did in many years. So, I'd be a total idiot for being upset because SMath development is, if not frozen, at least hugely slowed down. I'm anyway totally grateful to Andrey for the terrific job done, and for giving it for free.
On the other hand, in more than one year, the money we donated to the project (I did a small donation of course) amounts to 1746USD. Probably a comparable amount to one month salary for a software engineer. Definitely not enough to ask to Andrey to give up with different jobs and dedicate all his efforts to SMath.

What we can do? One option would be to opensource the SMath code, hoping that a community could take care of the software by adding new features.
I love opensource software, but I think that Andrey has the right to keep for himself the results of his talent and work. So I do not think it would be fair to ask him to release the code.
But probably there could be a different approach: in case we found out some new developers, enough skilled to be productive with the existing code, Andrey would have to share the source code only with few people (after signing an non disclosure agreement), and continuing to be the Project Leader.
This way it would be possible to improve the software, possibly linking existing tools to the SMath nice GUI: I think, for example, about linking Maxima and Octave to SMath.

I'm not a programmer, so I could not be able to help directly.
I'd like to have Andrey's and users opinion about this topic.

Thanks

I think that Maxima might have a lot to offer SMath, but equally SMath might have a lot to offer Maxima. The only problems would be that Maxima is Open Source and written in LISP. Having said that there was an attempt to incorporate Maxima into Geogebra and it did work.
There is a definite ambition amongst some of the Maxima developers to produce a Mathcad like interface. At the moment wxMaxima comes close but is a bit awkward, although I find it exteremly useful for teaching engineering students Calculus topics.
Being a newcomer to SMath I will spend some time using it both myself and with students as it certainly is an excellent program. So far symbolic integration (ODE solver) is the only function I really miss.
Mathcad has now become very difficult to use in education due to PTC's draconian licensing agreements. SMath, with more features would be excellent and I am sure would be widely used in, especially, engineering education.

Peter