The paradigm shift from galaxy-selected to quasi-synoptic surveys led to a revolution in the study of optical transients. The Palomar-Transient-Factory (PTF) experiment has played a distinguished role in this endeavour. PTF was a fully-automated, wide-field survey using the 1.2-m Samuel Oschin telescope (P48) at Palomar Observatory, California (USA), and was operated between March 2009 and the beginning of 2017. This experiment scanned an area of ~27000 deg² to a depth of m(R)=20.5 and m(g')=21 (5 sigma) every five nights. The goals of the survey have been to systematically explore the supernova (SN) phase space and search for exotic transients. The success of PTF is based on having full control over the robotic transient detection and the dedicated follow-up resources to perform spectroscopy and multi-band imaging. Between 2009 and 2017, PTF has discovered over 900 core-collapse SNe. Here, we present the first results from Data Release (DR) 1. DR1 includes 103 core-collapse SNe detected between 2009 and March 2010 and provides photometry (primarily in g' and R), spectra (in total over 250) and host photometry in 12 different bands from 200 to 4000 nm for each object. This rich data set will give the astronomical community the opportunity to gain a much-improved understanding of why and how massive stars explode as SNe.