Hipchat and Skype were two popular applications that I used today that don't run on OpenBSD. I ran them on my laptop with an nvidia GPU, which isn't wonderfully supported by linux, but it's even less supported by OpenBSD. Nvidia is a pretty damn common brand. Flash, for all it's sins, is still popular and not supported properly. Steam is another popular application that doesn't work on OpenBSD. Admittedly you said open source, but frankly, I didn't. I said 'applications people use'. It's utter bullshit to move the goalposts and then chide me for inaccuracy.
Then there's virtualisation software in general, which is increasingly popular and widespread, which OpenBSD doesn't support well, if at all (kvm, xen, vmware, virtualbox, and friends. qemu by itself is s.l.o.w.). Docker and other containers are really taking off at the moment and have a lot of mindspace, though admittedly these are linux-specific. Openstack is another significant emerging bit of software that doesn't support BSD as a host.
Then there's plenty of stuff like this http://blog.lxde.org/?p=1111 where OpenBSD could be better supported but is a broken experience. Legitimate reason, sure (not enough eyes), but it's still a broken experience.
Then there's virtualisation software in general, which is increasingly popular and widespread, which OpenBSD doesn't support well, if at all (kvm, xen, vmware, virtualbox, and friends. qemu by itself is s.l.o.w.). Docker and other containers are really taking off at the moment and have a lot of mindspace, though admittedly these are linux-specific. Openstack is another significant emerging bit of software that doesn't support BSD as a host.
Then there's plenty of stuff like this http://blog.lxde.org/?p=1111 where OpenBSD could be better supported but is a broken experience. Legitimate reason, sure (not enough eyes), but it's still a broken experience.