If the Gens32 Surreal is now the best SEGA Genesis, Mega-Drive (MD) emulator for Windows only, then Gens is the earliest and best one for Windows and Linux all the time. And it's a cross-platform, open-source Sega Genesis / Sega CD/ MD / Sega 32X emulator for DOS/Win32/UNIX.

Snes9x is a great freeware video game emulator for North American Super Nintendo Entertainment System (SNES)/Japanese Super Famicom (SFC), and it's the only SNES emulator available for Mac OS X system. And I think it's also the best one for Windows users.

As a matter of experience, many people (especially for personal webmasters) have deeply understood the installation of Apache server on localhost is definitely not an easy thing, not to mention adding a MySQL, PHP or Perl component, harder. Nevertheless, luckily there are tools similar to XAMPP integrate frequently-used development environments into one package.

Once learn about Beyond Compare (BCompare),  you will find that using UltraCompare (if you ever used) is really a physical work - fatigue our eyes too much, then you will fall in love wth Beyond Compare and can't do without it.

NASA World Wind popularly known as a magnifying glass of earth (it is the crystal of variety of technologies), co-produced by the NASA, similar to bird's eye view tool of Earth Viewr 3D (discontinued), but more powerful, authoritative and completely free.