We present numerical algorithms to image passive acoustic sources in the absence of the speed of sound information. The measurement is the boundary wave field and its spatial derivatives. Under certain conditions, the speed of sound can be jointly reconstructed. The algorithms are validated with numerical examples. An application scenario is the Photoacoustic Tomography, a multi-wave imaging modality where acoustic sources in unknown biological tissue are to be imaged. The presentation is based on joint work with G. Huang, J. Qian, S. Qin, R. Wang.