-Optimized node search routine
-Offensive NPC spell casting
-Defensive NPC spell casting
-NPC buffing
-NPC flee mechanics
-NPC emergency casting mechanics
-NPC return home routines
-Dynamic zonewide agro list system
-Various level of server-side "green" consider levels (barely green to mostly green; used with agro/assistance)
-Outdoor mini-dungeon pathing
-Leash system (yes, this was in classic, you probably never noticed it due to your runspeed)
-Spell resistance system
-Mob push system
-Spell stacking system
-NPC special attacks (double, triple and quad attack)
-Mitigation system
-Evasion system
-Weapon procs (based on "procs per minute" with a small bonus from DEX)
-Item and spell haste
-Default KOS levels for all NPC races
-AC cap system
-NPC summon
-NPC enrage
-NPC flurry
-NPC rampage
-Haste cap system
-NPC special attacks (kick, backstab, HT, LoH and bash)
-NPC immunities (magic, slow, charm, fear, mez and stun)
-Loot messages
-Equipping items on NPCs
-NPC weapon management system
-NPC default weapon/armor textures

-Spell types:

    -Disease counters
    -Poison counters
    -Shrink/Grow
    -Slows
    -Faction modifications
    -Hate modifications
    -Bind affinity
    -Shadow step
    -Invulnerability line
    -Buff proc effects (See: Boon of the Garou)
    -Spin stun
    -Eye of Zomm line
    -Corpse summoning
    -Reclaim Energy line
    -Weather modifications
    -Call of the Hero line
    -Summon companion
    -Death save line (See: Divine Intervention)
    -Succor
    -Fear (PC and NPC alike)
    -Charm (PC and NPC alike)

-Starting character locations
-NPC attack reservation
-Pet management
-Reward system for kills (exp, loot and faction)
-Shared memory system (server-side)
-Auto inventory looting system
-Group EXP system
-Taunt
-Dropped item support
-NPC skill levels
-Outdoor/Indoor spell support
-Dropped coin support
-Bulk spawn packets
-Vendor pricing system
-Debuff hate calculation system
-Partial resist system
-Added over 30,000 items to the database
-Fixed a countless number of zone and world crashes