What are the visa & residency requirements in Muscat?

"In order to visit Muscat, visitors must obtain a visa prior to arrival. The process of applying for a visa involves submitting an application form, a valid passport, and a passport-sized photograph. Depending on the purpose of the visit, additional documents may be required. In order to obtain residency in Muscat, Oman, applicants must submit an application form, a valid passport, a passport-sized photograph, and proof of employment or financial means. Depending on the purpose of the residency, additional documents may be required. Once the application is approved, the applicant will be issued a residency permit," remarked another expat in Muscat, Oman.