I am sceptical that this is a Bornean White-bearded Gibbon, given the colouration of the animal. It just looks like an Agile Gibbon. White-bearded Gibbons are brown, and even in darker individuals the limbs are paler.
@Chlidonias Thank you! Yes, this animal is from Ragunan. They have 1.1 in the Schmutzer Primate Center. The Snowleopard's foto is from Gembira Loka. We saw only one young animal there.