Classes Changes

Assassin

Gains Assassin Spells: Level 1-4, based on Intelligence. Arcane caster (spell failure for armor penalty will be considered).
Removed previous spell like abilities

Progression:

Level 1 spells at Assassin's level 1: Camouflage, Expeditious Retreat, Flare, Ghostly Visage
Level 2 spells at Assassin's level 3: Cat's Grace, Darkness, Ultravision, Fox's Cunning, Invisibility
Level 3 spells at Assassin's level 5: Displacement, Hold Person, Poison
Level 4 spells at Assassin's level 7: Freedom of Movement, Haste, Improved Invisibility, Mass Camouflage

Barbarian

Barbarian rages have been reworked.
If going PURE (40 levels in Barbarian), a barbarian will get:

Feat Reckless Berserker: grants +2 STR, +2 CON and Mind Immunity during Mighty Rage

Bard

Bard Song scales like in vanilla, but if going PURE (40 levels in Bard), an additional song step is unlocked.

LVL 40 Bard Song - Prerequisites: Level 40 Bard, 109 Perform:

Gets: +4 AB, +4 Damage, +5 Will, +4 Fort, +4 Reflex, 60 Temp HP, +8 AC, +20 to ALL Skills, +3 Regeneration
This Bard song step also applies to Curse Song, applying the same numbers as debuffs on hostile targets (except regeneration).

Blackguard

Gains the same spellbook of a paladin, with these changes:

No healing spells: Gains Inflict wounds instead
No Holy Avenger spell
Removed previous spell like abilities

Progression:

Level 1 spells at Blackguard level 4: Bless, Bless Weapon, Deafening Clang, Divine Favour, Endure Elements, Inflict Light Wounds, Magic Weapon, Protection from Alignment, Resistance, Virtue
Level 2 spells at Blackguard level 5: Aid, Aura of Glory, Bull's Strength, Eagle's Splendor, Inflict Moderate Wounds, Remove Paralysis, Resist Elements
Level 3 spells at Blackguard level 6: Dispel Magic, Greater Magic Weapon, Inflict Serious Wounds, Magic Circle Against Alignment, Prayer, Remove Blindness/Deafness
Level 4 spells at Blackguard level 7: Contagion, Death Ward, Freedom of Movement, Inflict Critical Wounds, Neutralize Poison, Poison

Divine Champion (Ex Champion of Torm)

Divine Champion Feats have been improved.

Can select Great CHA as bonus feat.

Cleric

Cleric Domains have been heavily adjusted trying to give some more balance and use cases. Many spells have been added to each domain from Druid and Wizard/Sorcerer spell books, trying to make each domain unique.

Cleric domains special abilities cannot be dispelled
Domains like air, earth, fire, water, when using Summon Creature, if that elemental is the elemental of the domain, the creature will receive full UNIQUE buffs (not nerfed like for the Animal domain, which gives the bonus to all summons regardless)
Cleric Domain Spells are now compatible with the Rod of Fast Cast
Special domain abilities have been improved too. They are listed under the Feats page.

If going PURE (40 levels in Cleric), a cleric will get:

Feat High Priest: grants +3 DC to all Cleric spells

Also:

Clerics have access to Great Charisma feats.

Fighter

Can get Great STR and Great CON as bonus feats

If going PURE (40 levels in Fighter), a Fighter will get:

Feat Veteran: grants +4 STR, +4 AC, +4 Fort Save

God's Eye Scout (Harper Scout Rework)

Default Harper Scout has been reworked. It is now an utility class that can fill many different builds, based on your needs!

Monk

Some Monk Feats have been improved.
If going PURE (40 levels in Monk), a Monk can select 1 feat between this list:

Way of the Bull: Prerequisite: Monk 40, Str 28+, Weapon Focus Unarmed or Quarterstaff.

Specifics: Monks who chose this Way gain +2 to strength and constitution, as well as +4 to their attack rolls.

Way of the Tiger: Prerequisite: Monk 40, Dex 28+, Dodge.

Specifics: Monks who chose this Way gain +8 to their attack rolls, but lose 3 AC.

Way of the Owl: Prerequisite: Monk 40, Wis 28+, Zen Archery.

Specifics: Monks who chose this Way gain +5 to their attack rolls and +4 to saves, but lose 2 AC.

Paladin

Can get Great CHA as bonus feat

If going PURE (40 levels in Paladin), a Paladin will get:

Feat Guardian Angel: gains +4 CHA and +2 AC

Paladin Summon Mount feat has been changed, and now works with the same logic of the custom Mounts System.
Check Feats Changes for more info.

Pale Master

PM level 30: Gains additional permanent +2 Natural AC
PM level 30: Gains a stronger summon with Summon Greater Undead

Red Dragon Disciple

RDD Level 30: Gains additional permanent +2 Strength, +1 Constitution & +1 Natural AC
RDD Level 20: Gains additional permanent +2 Strength, +1 Constitution & +1 Natural AC

Ranger

Gains level 5 spells: Awaken, Summon Creature V, Vine Mine, Monstrous Regeneration
Bane of Enemies has been improved

If going PURE (40 levels in Ranger), gets:

Feat Improved Evasion: Gets the Improved Evasion property
+4 DEX at level 40 (if PURE, with 40 Ranger levels)

Rogue

If going PURE (40 levels in Rogue), can select between 2 feats:

Feat Accurate Strike: grants +5 AB
Feat Hide on Plain Sight: grants the Hide on Plain Sight ability
+2 DEX, +2 CON received at level 40 (if PURE, with 40 Rogue levels)

Also:

Rogues have access to Great Dexterity feats.

Shadow Dancer

Shadow Dancer Feats have been improved.

Can select Great DEX as bonus feat

Shifter

Gets Move Silently as class skill
Gets improved shapes at shifter level 30
Can select Spell Focus feats while leveling as Shifter

Wizard

A wizard going PURE (40 levels of Wizard), will have all its spells DC increased by 3.