If you had the fortune (or misfortune, as it sometimes was) to play Eve shortly after launch, you’d remember that missiles used to be very, very different from today — and different from any other weapon system in the game at the time.
Missile launchers existed in similar varieties and meta-levels as today, but had names that denoted their capacity. For example, all heavy launchers had a 50m3 capacity for ammo, and all had names starting with H-50. (For example, “H-50 ‘Arbalest’ Heavy Launcher”.) Likewise, you had the M-12 Standard Launcher, the A-3 Assault Launcher, S-110 Siege Launcher, and so on. The crucial difference between those days and today is that any missile launcher could load and fire any ammunition that it could fit in its bay.
For example, a single reload of a plain M-12 Standard Launcher I could hold your choice of:
- 40 rockets
- 12 light missiles
- 2 heavy missiles
- 1 cruise missile
Regardless of what missile type was loaded in it, it’d fire every 14 seconds before skills. The same was true for larger launchers; a meta-0 siege launcher could hold 10-20 cruise missiles / torpedoes or 40ish heavy missiles or hundreds of light missiles/rockets, but always fired every 20 seconds before skills. In general, smaller launchers featured faster firing rates (meaning higher spike DPS) but had less flexibility and more frequent reloads.
Assault launchers were particularly different back then: they had frigate-sized fitting requirements, and were intended to be a midpoint between the standard launchers and the rocket launchers of the era. The rocket launchers in retail launch and Castor had a tiny capacity and could only fit 3-4 rockets per reload, but had miniscule fitting requirements and fired incredibly fast; assault launchers were roughly in the same space that rocket launchers occupy, with the added bonus of being able to load 4-5 light missiles if you needed to engage at long range.
With missiles working like this — and with the fact that missiles of this era were AOE weapons with splash damage — the dominant frigate of the era was a Kestrel with four standard launchers, loaded with cruise missiles. Loading cruise missiles meant that they could only fire off a single volley before reloading, but it allowed them to put out extremely high spike damage: A single cruise missile of the era did 300 damage to targets at its center, meaning that a single volley of four cruises was sufficient to one-shot frigates and smaller industrials.  Stow a few lights in the cargohold just in case, and you were good to go! Needless to say, cruise Kestrels were fantastic for high-sec suicide ganking as well, where they were known as “KamiKestrels.”
Eventually, during the Castor Period, missiles were refactored into the groups that we know and love today. Some collectors still have Kestrels squirreled away with cruise missiles loaded in their launchers; however, using them in combat is considered an exploit.
1: At this time, all ships had roughly 1/3rd of the base HP that they do today, across all sizes and classes. CCP would eventually bump up the base HP for all ships during Red Moon Rising, in the interest of making combat take longer and be less brutal; from there, most ships have slowly crept upwards in base HP over repeated rebalances.