@ton Not self-hosting, but a friendly alternative to Slideshare could be https://zenodo.org

There are other open repositories for scientific documents that are open source.

Dataverse: Danny Brooke, Harvard University
DSpace: Maureen Walsh, The Ohio State University
EPrints: John Salter, University of Leeds
Fedora: David Wilcox, LYRASIS
Haplo: Tom Renner, Haplo
Invenio: Lars Holm Nielsen, CERN Islandora: Mark Jordan, Simon Fraser University
Samvera: Jon Dunn, Indiana University