I don't know if this is official, but it says that it is DotA version 1.0.
Ladder heroes and most original ladder items, map by Eul's.
I'm currently still using wc3 1.20e, try using version switcher if you can't play with 1.24.
Other notable changes I had from 6.27 till 6.64, I haven't played 6.65 yet.
Once aegis was an item that can be bought, with DR you are already the winner.
Denying creeps totally denies experience. It is possible that you are level 10 and your enemy is still level 1.
Blink dagger doesn't have the 3 sec restriction.
Power threads doesn't have stats for str/agi/int before.
Eul's upgrade into Guinsoo before, and are tributes to the first map developers
Roshan doesn't level up. It is very strong that only few heroes can defeat him 1 on 1.
Alchemist's stat gains are just as good as other heroes, but now he has one of the lowest.
Tp scrolls cause the structure being teleported at invulnerable.
That's all I can remember for now.
Here is the map I'm telling:
DotA Allstars v.1.0.zip
I hope that helped.