Iban language is spoken by the Iban but don't be supprise if you visit Sarawak you will find many other races such as Chinese, Malays and other Dayak tribes speak Iban also. The language is understood my many Sarawakian maybe because it has some similarities to Malay language especially the Sarawakian Malay.
'Previously during the colonial regime (1946-1963), the Iban language was recognized and even used during the Council Negeri meetings. The Borneo Literature Bureau was set up to help popularize the language through its Iban magazine called Nendak and through the printing of Iban books.'
'When Sarawak obtained her independence through the formation of Malaysia, the Borneo Literature Bureau (BLB) was abolished and in came Dewan Bahasa dan Pustaka (DBP) some time 1978 to take its place. The abolishment of BLB saw several hundreds of Iban books and magazines destroyed.' (Source from thebrokenshield blog).
But after vigorous efforts of the Iban Comittee, the language began to be accepted again by the government and the teaching of the language in primary and secondary schools were approved until today and it is tested in PMR and SPM examinations. However, from my experience, even if the Iban is my mothertongue, it is hard to score due to the difficulty to access the reading materials in Iban. In fact, the Iban dictionary is also hard to find. Plus, Iban may be a language but it also has different dialects in different areas in Sarawak. For example, 'you 'in proper Iban language is 'nuan' but mostly spoken as 'dek' or in areas such as Kota Samarahan, Sadong and Lundu, you is 'kuak'. The differences in term may be minor but the phrases of Sibu Iban may sometimes mean something else in Sadong Iban. Unique, isn't it?