Using XAMPP on one machine. Multiple virtual hosts defined. One per project. Format is .local

For example:

apple.local
microsoft.local
client-site.local
our-own-internal-site.local

All works perfectly from that one machine. I now want to have other systems within the network access the various sites.

The main reason for wanting to do this is to be able to test site functionality and layout from mobile devices without having to upload partial work to public servers.

I can access the main XAMPP default site by simply entering the IP address of the XAMPP machine in, say, Safari on an iPad. However, there is no way to reach .local that I can see.

Would this entail setting up a DNS server within the network? We have a mixture of Windows and Mac machines. No Linux. The XAMPP machine is Vista 64. I don't want real external internet access to be affected in any way, just ".local" pointed to the XAMPP machine if that makes sense.