Shared with you
There was a level of friction between fans of Babylon 5 (1993) and this show. Babylon 5 (1993) fans felt that writers for this show had stolen many aspects of Babylon 5's premise (occurring recently after a war or occupation, episodes taking place on a space station not located in Earth territory, the cast discovering an ancient malevolent race that would become a major threat, the overall story of the show being less reliant on story-of-the-week episodes, and more of an overarching story arc, et cetera), asserting that Paramount Pictures had rejected J. Michael Straczynski's proposal of Babylon 5 to them in the late 1980s, but used certain details of the pitch by inserting them into the story and premise of this show. There was a concerted effort to bury the hatchet, especially by having Majel Barrett (widow of Gene Roddenberry) appear on Babylon 5 as an alien prophetess who spoke on behalf of her recently deceased husband (a nod to Roddenberry, who had passed away a few years before her appearance).
Kira was a last-minute addition to the cast. The original plan was to include the Star Trek: The Next Generation (1987) character of Ro Laren, but Michelle Forbes didn't want to do a series at the time.
Although we only rarely see it, there is an ATM in Quark's bar. It dispenses the various types of currency used by major races visiting the station: Federation credits, Bajoran litas, Cardassian leks, and Ferengi latinum.
Colm Meaney was initially reluctant about signing onto the series. Meaney was comfortable playing O'Brien on an episode by episode basis for Star Trek: The Next Generation (1987), and at the time, was unsure if he wanted to play a full time television role.
Armin Shimerman (Quark) and Marc Alaimo (Gul Dukat the Cardassian) appeared as one of the first actors to portray members of their respective species, and both appeared on Star Trek: The Next Generation (1987). Shimerman played the Ferengi officer Letek in The Last Outpost (1987) while Alaimo played the Cardassian officer Gul Macet in The Wounded (1991).
Constable Odo was originally envisioned as a young Clint Eastwood type. When Rene Auberjonois was called in for his audition, the casting director told him that none of the previous actors had been "grouchy enough". So Auberjonois improvised his lines using his most gravelly voice, and secured the role. Odo's scoff eventually became such a character trademark that the screenwriters would often script it into his lines (as "harrumph!"), much to Auberjonois' annoyance.