The grey and white cat is Greypatch, the black cat is Mama Cat. I was particularly pleased to get her neutered, she's responsible for at least two litters in the neighborhood over the past three years.
The orange cat is Sardines. Greypatch used to be pretty aggressive towards him, but a positive affect of neutering (aside from no more kittens) is being less territorial as testosterone levels drop. Greypatch still doesn't really like him, but will tolerate his presence.