Ambient music improvements
"Creative" music may now play in survival mode. When a music disc is played in a jukebox, in-game ambient music will be stopped and prevented from playing so that you don't get two tracks playing at the same time.
Automatic recipe unlock
All recipes will be available on login. This was the first feature written for 1.14 before Quark was developed as I couldn't live without it. Quark's implementation is better, so this feature will automatically disable itself if Quark is present.
Cauldron water source
Cauldrons act as a permanent water source for buckets and bottles when the player is sneaking.
Composter improvements
Composter inputs and outputs can be added by the configuration file. By default, rotten flesh is compostable and there is a chance for more bonemeal and mushrooms to be output when the composter is full.
Emerald block opens trades
Right click a villager while sneaking and holding a block of emerald to open all the villager's closed trades and regenerate some of the villager's health.
Extra music discs
All in-game ambient music by C418 is available on music discs, including the "underwater" tracks added in Minecraft 1.13. These music discs are dropped by zombies that were killed by skeletons.
Husk improvements
Husks can now spawn underground in their biomes and also have a chance to drop sand when killed.
Leather armor invisibility
Leather armor is now completely invisible and does not increase mob awareness when drinking a Potion of Invisibility, giving you a bit more protection while you ninja.
Mobs affected by beacon
A beacon with the secondary effect of Regeneration will heal all tamed, friendly and neutral mobs in the area around it. With the secondary effect of Strength, all nearby monsters will receive Weakness.
No anvil minimum XP
This small change to vanilla code allows anvil recipes to not require at least 1 level of XP. It fits better for certain actions, such as tallow increasing durability.
Pickaxes break pistons
Pickaxes are now the effective tool for breaking pistons and sticky pistons, rather than no effective tool.
Remove Nitwits
Prevents nitwits from spawning as new villagers. It also converts any nitwits in freshly loaded chunks to unemployed villagers.
Remove potion glint
Removes the enchanted glowing effect from potions so you can actually see their true color.
Sponges reduce fall damage
Landing on sponge absorbs some of the player's fall damage.
Stackable enchanted books
Enchanted books can stack up to 16 making them sortable.
Stackable potions
Potions, water bottles, potion bases (mundane, awkward etc) and their splash/lingering varieties can stack up to 16 making them sortable and more convenient to carry around.
Tamed animals no damage
Tamed animals no longer take direct damage from players. They still suffer secondary effects, such as potion effects from a tipped arrow.
Use Totem of Undying from inventory
As long as a Totem of Undying is in your inventory (rather than specifically your main- or off-hand) it will be consumed to protect you from death.
Witches drop luck
A witch has a slight chance to drop a Potion of Luck when killed by a player.