PBS

...and a grant from The Cheat

Within the Homestar Runner body of work, there are a number of references to PBS or to shows which appear on PBS, or simply public broadcasting.

Appearances

The House That Gave Sucky Treats — Strong Bad dresses up as Carmen Sandiego, the titular character of the game shows Where in the World Is Carmen Sandiego? and Where in Time Is Carmen Sandiego? for Halloween.
Email morning routine — Strong Sad says he wants to "watch that show on public broadcasting hosted by that British guy".
Email autobiography — Strong Bad's intro ("This email is brought to you by a grant from The Cheat and the support of Viewers Like You") is a parody of the message heard at the start (and end) of most PBS television programs.
Email radio — Marzipan listens to a radio station titled "PRS" (Public Radio Sounds).
Email underlings — Strong Bad states he finds NOVA boring, making fun of an emailer's location, Nova Scotia.
Strong Badia the Free — Homestar Runner's "letter" to Marzipan, detailing the siege on the King of Town's castle is presented in a similar style to Ken Burns' 1990 documentary, The Civil War, complete with sepia-toned backgrounds and violin music.
Characters from Yonder Website — The cartoon starts with sponsor logos in a similar way to PBS donor logos.
Trogdor Was A Man — The scenes featuring two silhouetted Trogdor heads is a reference to a recurring segment of The Electric Company, a children's show that aired in the 1970s, in which two people would say part of a word to each other, with the letters coming out of their mouth in a similar fashion.

Teen Girl Squad Issue 6 — "3 noses?" may reference an episode of the Magic School Bus, in which the judges award points for the best smell with a score in "noses".
Email for kids — Homsar asking the kids if they want to "hear of [the song] 50 times more" may be a reference to the PBS show Teletubbies, in which whenever a "real-life" clip is shown, it is always repeated per request of the Teletubbies. Strong Bad also finds it absurd that the sender thinks he's intended for children, who watch "those shows on public television".
Email rampage — Strong Bad's "reading rampage" is a reference to Reading Rainbow.