Just months ago the i915 DragonFlyBSD graphics driver was years behind the upstream Linux kernel while in recent times a lot of headway has been made where the Intel graphics driver on this BSD operating system is just a few releases behind the upstream state.
With the DragonFlyBSD i915 driver up to Linux 4.2 comparability, there is initial Broxton hardware support, better Broadwell and Skylake support, progress on atomic mode-setting support, various DisplayPort improvements, lower execlist overhead, frequency boost tuning, and various bug-fixes.
Interestingly, while the latest open-source Intel Linux graphics driver now requires firmware blobs for operation, the DragonFlyBSD driver is going for a blob-free approach. Tigeot explained, "starting from Linux 4.2, a separate firmware blob is required to save and restore the state of display engines in some low-power modes. These low-power modes have been forcibly disabled in the DragonFly version of this driver in order to keep it blob-free."
It would be funny to see if GNU Linux-libre ends up trying to port the DragonFlyBSD i915 blob-free changes to their kernel. GNU Linux-libre folks recently complained about the Intel firmware blobs but didn't appear to be doing anything about it while DragonFlyBSD is coming up with a solution, albeit less than ideal.
More details via this Git commit.