Do you think Rachel and Darcy became [good] friends again?

I would like to think so :-) there is a book after called something blue which should explain it.

The part at the end of the movie doesn't happen in the book. I read Something Blue, they do not become good friends again, or even friends. I think they briefly talked on the phone (it's been awhile since I read it)

They never seemed to be that great of friends anyway. They seem like the type of friends that drifted apart a long time ago and they are only friends because they have been friends all their lives.

i took the last scene with the two of them at end and darcy does smile at her that things will get better for them

it's never Joan Van Ark- Marge Simpsons

Actually in the book, three days after they saw other again, Darcy gets pulled into an alley, raped, and murdered. Unfortunately, the last time Rachel saw her was in a coffin.

*SPOILER FOR THE BOOKS*
Sorry I'm on mobile and don't know if I can add the spoiler mask...
But I think that in Baby Proof (which centers around completely different characters) Ethan makes an appearance talking to the main character Claudia, a book editor. He is writing a memoir of his life with his wife Darcy and his two sons and their daughter. I remember something in the book where Ethan explains to Claudia that he and Darcy take vacations with Rachel and Dex (I think they have children too). So eventually they do get over it.

No, I don't think they would ever have that close friendship again. I'm honestly amazed they managed to have such a close friendship as long as they did. However, I think that was only possible because Rachel was willing to give give give, which worked perfectly for a taker like Darcy. Even if Rachel hadn't betrayed Darcy, I don't think their friendship would have lasted much beyond the point of Rachel deciding to step out of her shadow and go after what she wants, even if it's the same thing Darcy wants. That dynamic just wouldn't work between them.

As someone who lived thru a similar experience, I'd say no. Best friendships don't survive this kind if betrayal. Even when you forgive them in your heart, the trust is gone forever. As for me, the desire to be in that person's presence just wasn't there anymore...even though I still had lots of love for them.

Nah they would never become friends again at all. The scene at the end with Rachel smiling was just like saying "You do your thing because I'm good now" It may have even been forgiveness but it was not an invitation to be friends. It would be too painful and weird.