>>31
There's plenty of old DOS applications that just don't work in DOSBox. That's because everybody was a cowboy in real mode - they hooked interrupts, switched to protected mode, setting up their own mini OS to get more memory, and various other tricks which DOSBox just can't handle. When I want to run such applications, I just fire up my DOS VM. Now that is reliable.
Of course, who would write 16bit x86 web applications. You'd probably write 32bit x86 or 64bit x86, and maybe add a portability layer(futile as it is), if you wanted to support both *nix or win*. Or you could ... you know, write in C. Wait, you're doing web development, performance only matters here for very large scale sites, so you can even use SLOWASFUCK if you wanted, or you could pick a reaonably fast compiled or JITted general purpose language which already has a bunch of web frameworks/web servers written for it, and just use that and make your site in a few hundred lines of code, instead of going for high thousands by the road of asm or C.