Glyn has interests in several areas of English poetry (particularly that of the seventeenth and twentieth centuries) and in aspects of bibliography and textual scholarship. His publications include editions (chiefly from manuscript) of several seventeenth century poets (Henry Reynolds (1991), Richard Niccols (1992), Henry Hughes (1997) William Gamage (2002), Sir John Stradling (2003)), I poeti ferraresi nel Rinascimento inglese (1992), Francis Warner and Tradition (1981), Francis Wamer's Poetry: a Critical Assessment (1988), and A Bibliography of the Writings of Peter Russell (1995). He has published essays on, amongst others, Shakespeare, Marlowe, Bunyan, William Strode, Ernest Dowson and Basil Bunting (with Parvin Loloi). He is reviews editor of Acumen and general editor of The Swansea Review.
Glyn is currently supervising two research students in the fields of seventeenth century poetry and monstrosity in children's literature.