We present HapFACS (ver. beta), a new open source software and API for generating FACS-based facial expressions on 3D virtual characters that have accompanying lip-synchronized animation abilities. HapFACS has two main usage scenarios: First, with the HapFACS software, users can generate repertoires of realistic FACS-validated facial expressions, either as static images or as videos, Second, with the accessible HapFACS API, users can animate speaking virtual characters with real-time realistic facial expressions, and embed these expressive characters in their own application(s) without any prior experience in computer graphics and modeling. We describe how HapFACS (1) provides control over 49 FACS Action Units at all levels of intensity, (2) enables the animation of faces with a single AU or a composition of AUs, activated unilaterally or bilaterally, and (3) can be applied to any supported character in the underlying 3D-character system1. Finally, we provide details of evaluation experiments we conducted with FACS-certified scorers to validate the facial expressions generated by HapFACS.