Where do I go from here?

I have been in the IT field for almost 18 years. I started my career as freelance software developer by developing commercial software applications like financial accounting, inventory control, production, sales, payroll, manufacturing and many more in MICROFOCUS COBOL on DOS/NOVELL platforms. I was totally involved in development and support of these application consisting of approximate 5000 programs and 35 modules. I didn’t have time & need to upgrade myself.
I love the IT field but I need to maintain a decent salary/income to support a wife and 2 kids. What in the IT field hot? What can I study for the future? Which is the best platform/technology to develop stand-alone window based GUI commercial applications without keeping big overhead of cost of database and development environment? Thanks in Advance for your valuable suggestions.