The prosecutor from Abbottsville, Mr. Gilmer, seems to realize--as does Atticus--that the outcome of the Tom Robinson trial is a foregone conclusion. Early in the novel, Atticus tells his brother that
"the jury couldn't possibly be expected to take Tom Robinson's word against the Ewells... I think we'll have a reasonable chance on appeal, though."
We can assume that if Atticus is aware of this likelihood, then Gilmer is as well. Gilmer takes it easy on his first three witnesses--Sheriff Tate, Bob Ewell and Mayella Ewell. He makes sure they present the basic facts of the case, and then he leaves Atticus to try to disprove their statements. Gilmer is much harsher when he cross-examines Tom, repeatedly calling him "boy" and demeaning him at every turn. For Gilmer, it is an easy day for a prosecutor who is simply going through the motions in a trial where the outcome is already clear.
Scout describes Judge Taylor thoroughly, and she has probably gotten most of her information from her father. Atticus considers Taylor a fair man, though he sometimes acts "wrathfully," and he knows how he will react in court; for example, Atticus walks to far side of the courtroom and stares out the window when Taylor tries to calm Mayella Ewell. He knows it is best to "let Judge Taylor handle this one." Atticus also knows the reason Taylor chose him to represent Tom in the first place: Because he knew Atticus would "aim to defend him" to the best of his ability.
Scout describes Mr. Gilmer in this way:
The solicitor, a Mr. Gilmer, was not well known to us. He was from Abbottsville; we saw him only when court convened, and that rarely, for court was of no special interest to Jem and me.
So the children are unfamiliar with his tactics in court. However, when Bob Wewell is rude to him, Scout feels sorry for him, saying that Mr. Gilmer is just doing his job, like Atticus. Now, one can argue that he was doing the best he could to win his case. This is probably true, although he seems slightly more reasonable than many of the people in Maycomb regarding the issues of rape and crime. However, he also speaks condescendingly to Tom, calling him "boy" and dismissing his remarks. So, no matter how he personally feels about the trial, he will do everything he can to win it. He speaks with an air of hostility against Tom to capitalize on the prejudice already felt against him. This hostility is so strong that even Dill, who probably does not understand its source, can sense it. He breaks into tears and must be taken from the courtroom.
Atticus considers Judge Taylor a fair and sympathetic man. He is the one who appointed Atticus as Tom's defender in the first place, & Atticus is relieved that he is the sitting judge for the trial. He feels that Tom has a better chance with Judge Taylor than anyone else. Like Atticus and Mr. Gilmer, Judge Taylor is doing his job to the best of his ability. When Link Deas speaks up on behalf of Tom, Judge Taylor is ready to throw him out and declare a mistrial. He is also keenly aware of the sensitive nature of the proceedings, so he attempts to make everyone, witnesses and audience, comfortable.
Mr. Gimer is the prosecuting attorney in the book "To Kill a Mockingbird." He and Atticus are friends when they are not engaged in a courtroom battle. During the trial Mr. Glimmer presents as a gentleman who is looking in the best interest of the state. He meets some resistence from his own witness Bob Ewell. He maintains his composure during the man's rudeness. However, he does object when Atticus is trying to get Miss Ewell to reveal information. He tells the judge that Atticus is badgering the witness.
There is obviously a friendship between Atticus and the Judge because the judge's response is to respond in humor regarding Atticus. He does so with a smile.
Atticus and Mr. Glimmer leave the courtroom and meet to talk.