I've seen several of these threads go by, and since I haven't really seen anyone represent my view, I'll offer my opinion on Corruption. I'll assume the Corruption rules were written by Ian Sturrock, and I will base my opinion on the books I've read where he is credited (Atlantean Edition and Scrolls of Skelos).
The intention of Corruption can be debated. But all of the cases I've found(although I may have missed some, especially in the creature sections, which I have not read) in AE and SoS that require a Corruption save have one thing loosely in common. Close, peaceful contact with either a corrupting creature, or an object cursed or tainted presumably by such a creature. Since the term Corruption suggests embezzling government officials to me, I prefer to think of it as Taint, but that term has already been used in the D&D Oriental Adventures book
Sources of Corruption as per AE and SoS:
Peaceful contact with demons (including casting Demonic Pact, Greater Demonic Pact, or Vampire Transformation)
Being drained by a demon in a War of Souls
Peaceful contact with evil gods
Peaceful contact with creatures who have Corruption 10+
Peaceful, pleasurable contact with sorcerer who has Debaucher feat
5 min of conversation with sorcerer using the corrupt form of Projection
Securing and counting a tainted treasure hoard
Living in the glow of Green Fire Stones or Radium Gems for a week
Drinking water from the Zarkheba river
Also some aquired templates (Spawn of Dagoth Hill, Vampire, Child of Jhebbal Sag, Salome, Mummy of Ahriman) add Corruption. And aberrations and new life forms accumulate Corruption continually. All these creatures are arguably tainted anyway.
I know the rules of looting in The Free Companies deviate from the Taint theory, but that book was written by Shannon Kalvar. SK's take on this seems to be that evil acts bring with it Corruption. This is not intended to bash SK, but I personally don't agree with this, because common people have terrible Will saves, and many of the inhabitants in the Hyborian Age would consequently have cracked skulls with swollen brains or look like skin-covered skeletons. As an example, if a mercenary with a relatively low (+5) Will save rapes 4-8 pregnant women, he could easily end up with scales instead of skin. It is also worth noting that horrible spells like Black Plague and Summon Demon do not force Corruption saves.
A sacrifice is required for spells like Witch's Vigour, Eternal Youth, Unnatural Strength, and Vampire Transformation. It is also tied to spells like Awful Rite of the Were-Beast, Dance of the Changing Serpent, Draw Forth the Soul, Dance of the Cobras, Draw Forth the Heart, Invocation of Xuthalla, and Dance of Atali. Yet none of these spells except Vampire Transformation (which has Demonic Pact as a prerequisite) call for a Corruption save. So I disagree with Argo, and Rene and Sutek in the "Sacrifices" thread further down. In my opinion even multiple, tortured sacrifices should not force a Corruption save, unless the ceremony is attended by a source of Corruption.
Of course, it is risky to interpret a still living author, but if whoever wrote the rule wants to shed some light on this, he is welcome to.