Academic scholarly communication is the predominant business of researchers, scientists, and scholars. It is the core element of promoting scientific thought, investigation, and building up solid knowledge. The development of preprint platform web interfaces, server repositories of electronic scholarly papers submitted by their authors and openly available to the scientific community proposed a new form of academic communication. The distribution of a preprint of a scientific manuscript allows the authors to claim the priority of discovery, in a manner similar to the conference proceedings output, but also creates an anteriority that prevents protection by a patent application. Herein, we review the scope and the role of preprint papers platforms in academia, we explore individual cases, arXiv, SSRN, OSF Preprints, HAL, bioRxiv, EconStor, RePEc, PhilArchive, Research Square, viXra, Cryptology ePrint Archive, Preprints.org, ChinaXiv, medRxiv, JMIR Preprints, Authorea, ChemRxiv, engrXiv, e-LiS, SciELO, PsyArXiv, F1000 Research, and Zenodo, and discuss their significance in promoting scientific discovery, the potential risks of scientific integrity, as well as the policies of data distribution and intellectual property rights, the plus and minus, for the stakeholders, authors, institutions, states, scientific journals, scientific community, and the public. In this review we explore the scope and policies of the existing preprint papers platforms in different academic research fields.