Dell Latitude E5550:
Intel Broadwell i3-5010U @2.10GHz
Intel HD5500 graphics
8GB DDR3L RAM
Intel I218V LAN
Intel AC 7265 Wireless
OpenCore 0.7.3 and Clover r5138 with up-to-date kexts at time of writing.
Updated: Dell Latitude E5550.zip
Working:
Full graphics acceleration
HDMI output
Wifi and Bluetooth
LAN
Audio (speakers, headphones & HDMI)
Sleep with lid off and > Sleep
Brightness control
Multimedia button
Keyboard and touchpad (ALPS)
SD card reader
USB2.0 & USB3.0 ports (USB remapping required macOS installation because my laptop doesn't have camera so I've not remapped yet)
Battery Indicator and charger
Not working:
VGA output (unsupported)