Storm Eagle
The Storm Eagle Assault Gunship is the "middle brother" of Space Marine aerial transports, carrying twenty Marines as opposed to the Stormraven's twelve-plus-Dreadnought or the Thunderhawk's thirty. The Space Marines used loads of them during the Great Crusade, but the forge worlds that made them were destroyed during the Horus Heresy. This meant that the only Storm Eagles in use were those left over at the end of the Heresy, so you had to be from the First or Second Foundings to even have them and they were only seldom deployed, but those chapters who are friends of the Adeptus Mechanicus seem to be using theirs a lot more frequently, almost as if they're being made again...
Given how powerful all Space Marine aerial vehicles are, you'd think that they would make use of as many as they could by flying around empty ones modified for dropping bombs or holding more weapons/ammo to support their brothers on the ground. Or, hey, how about using the fuck-tons of chapter serfs to pilot air craft and drive tanks and shit so all the power armored super-soldiers can do what they do best. Kill shit with bolter and chainsword. Please note that this is exactly what the Legiones (not misspelled, blame Games Workshop) Astartes did and they conquered a million worlds almost single-handedly in about two or three centuries.
It's a Forge World product, created to beef up the Space Marines' section of Imperial Armour Aeronautica (as if the Marines didn't have enough toys already), and to give some non-Apocalypse aerial transport to those Chapters that aren't Blood Angels or Grey Knights (including Chaos Space Marines). It also spots a twin-linked Heavy Bolter, an array of Missile Launchers and, optionally, two twin-linked Lascannons or four krak missiles.
Clearly effective at killing any enemy vehicles present at a drop-zone and saturating the surrounding area with missiles and heavy bolt shells before deploying is Marines.
Its appearance should always be accompanied by an epic guitar riff.
Roc Pattern
The Roc Pattern is unique to the Minotaurs Chapter, and is a dedicated tank hunter. It loses six seats to hold additional fuel and ammunition. Beyond the original Storm Eagle's loadout, the Roc Pattern comes with lascannons standard and replaces the Heavy 2 5" blast missile launcher with a Heavy 4 twin-linked krak launcher. It also gets a BS boost for attacking ground targets.
Fire Raptor
Suddenly Forge World guys realized that people run Storm Eagles empty more often than not, being of more interested in using them as a fire platform than as an extremely risky transport (because S10 AP2 autohit for every passenger if it explode midair suck), so they cut out the transport capacity, armed it with a twin Avenger bolt cannon (aka "fuck marine gun") instead of nose twin HB, and replaced the missile pods with two sidegunner sponsons with four HBs each, and named it the Fire Raptor. This thing is a flying rape machine against any infantry lighter than terminators. There is currently no rules for this beast, but we expect it to have something like double POTMS to fire each sponson independently.