Do you or have you ever used Jade and what are its advantages and disadvantages of it in your opinion? For example:
Yes, I have to some extent, although it was not extensive and it was about 10 years ago. However, my $0.02 worth is:
Jade is very easy to learn - There's quite a lot to be said for a system where you can fit the class library reference into a single manual.
The integrated OODBMS makes data access simpler for the application developer, but it is not as good as a RDBMS for reporting. If doing a JADE/OODBMS project, consider adding a data mart or data warehouse feed if you have substantial MIS requirements.
The OODBMS is pretty orthogonal to a MVC architecture. Jade does support ODBC if you want to use a conventional RDBMS platform but I'm not aware of any O/R mapping tools available for it.
It is very focussed on business applications - the company's original product was a 4GL called LINC and this mindset is somewhat visible in the system. It is not as general purpose as Delphi or even .Net, but it is a great deal simpler.
The GUI toolkit is a bit simplistic - for example, as far as I can tell it has nothing equivalent to a user control. It's certainly adequate to make a decent user interface, but you will find it lacks the flexibility of WinForms or the VCL. I can't think of anything in the architecture that would make it difficult to implement a MVC framework.
Unless you want to scale to a big .com (in NZ?) you shouldn't need clustering for performance. A large server like a DL585 or DL785 on a SAN should be able to cope with thousands of punters on JADE. On a system like that the biggest infrastructure cost will be the SAN. More reasonably, a mid-range two socket box with adequate disk bandwidth should be able to cope with any workload you're likely to encounter in New Zealand. Bear in mind that Stackoverflow is running on quite modest hardware.
The last time I looked a developer seat for JADE was about 6,000 pesos. This may or may not still be the case. You would have to contact Cardinal to get indicative runtime license pricing.
JADE is the closest thing I can think of to a modern 4GL. If you work to the system's strengths you can get great productivity and a reasonably clear and maintainable code base. If you try to shoehorn it into pretending that it's .Net you will probably tie yourself in knots.
I haven't used Jade, but I've used other OODBs, and I have to say they are generally far superior to even the best ORDB-mapping kludges.
It's easier to drive nails with a hammer than with a rubber duck, even if its just a mediocre hammer and a really fine duck.
-- MarkusQ