Skype is a free program that uses the latest P2P technology to bring affordable and high-quality voice communications to people all over the world.
You will need to make sure you have latest ports tree before you attempt to install net-im/skype4. The FreeBSD Handbook is a place where you need to visit and read.
First you should uninstall linux-f10* ports and its dependencies. To make it easier, you can use portmaster(8) for that purpose:
# portmaster -e target_port
Before starting to install, be sure that you add both lines to /etc/make.conf:
OVERRIDE_LINUX_BASE_PORTS=c6
OVERRIDE_LINUX_NONBASE_PORTS=c6
Change the compatibility level of the Linux kernel OS release by running the following command:
# sysctl compat.linux.osrelease=2.6.18
Also add this sysctl(8) variable to /etc/sysctl.conf to make the change permanent:
# echo 'compat.linux.osrelease=2.6.18' >> /etc/sysctl.conf
Note that it's necessary to have enabled LBC before you can install net-im/skype4 port. Read for further details the corresponding Chapter 11. Linux Binary Compatibility of the FreeBSD Handbook.
As Skype depends on linprocfs(5), check if it can be loaded and mounted by running:
# kldload linprocfs
# mount -t linprocfs linproc /compat/linux/proc
If it works, add this line in /etc/fstab
linproc /compat/linux/proc linprocfs rw 0 0
You will need to merge the skype4-ports into your /usr/ports. Now you are ready to install net-im/skype4.
# portmaster net-im/skype4
If you want video calls support you should also replace linux_videodev2.h header from multimedia/linux_v4l2wrapper-kmod port:
# cd /usr/ports/multimedia/linux_v4l2wrapper-kmod
# make patch
# mv -i /sys/compat/linux/linux_videodev2.h{,.bak}
# cp -i work/linux_v4l2/linux_videodev2.h /sys/compat/linux
Then rebuild/install the kernel. However, I should clarify that this patch is already applied for FreeBSD 10 and CURRENT.