BMD - "Boyevaya Mashina Desanta" - literally Battle Vehicle Desant. [Sounds as if it should be in some loopy anime feature with moody teenagers driving huge robots - but I digress]
In this context Desant refers to airborne operations and this is a vehicle designed to deliver BMP levels of firepower but be para-droppable or heliborne. Consequently it has internal volume suitable for carrying a section of ants and laughably thin armour. It can usually be seen with the section sitting on top. Nevertheless, compared to the vehicles Paras are normally equipped with it's quite impressive.
It is currently available in three flavours, BMD-1, BMD-2 and BMD-3.
To keep the weight down (for airdropping), the metal used for the hull in early versions was a magnesium alloy. Magnesium burns like a bitch as the Afghans found when they started potshotting the things with RPGs. Later versions had the hull made out of aluminium.
Serious anorak details can be found at: