bler144: No mods. I have no idea what TuTu/BGT is, so I'll presume vanilla, and gave the version in the OP.
Bookwyrm627: TuTu and BGT are two different ways to start in BG1 and play all the way through ToB in a (more or less) seamless way. No importing characters/parties, etc. The stickies have more details.
Actually, strictly speaking, TuTu and BGT (Baldur's Gate Trilogy) are technically Baldur's Gate 2 (not 1) mods. TuTu is a total conversion mod the converts BG2 into BG1, so you're essentially playing through BG1 with the BG2 engine, which means you trade the quirks of one engine with the quirks of another. (It also includes some "fixes" that I happen to disagree with, and no option (AFAIK) to disable them.) BGT does something similar, but instead of replacing BG2 entirely, it instead appends the converted BG1 to the beginning of the game.
In any case, this does affect the gameplay; for example, in TuTu/BGT, the game pauses in the inventory screen (unlike BG1 where it unpauses), and you are limited to 5 summons at a time. Also, if you are going to further mod a TuTu/BGT game, you need to look for BG2 mods, not BG1 mods (unless the BG1 mods explicitly mention compatibility with TuTu and/or BGT).