A history of Roman sword development?

[Luka Borščak]

Out of interest, when did gladius stop being used in the West and what did the last types look like? Are there any good online resources?

I think the last gladii that would be instantly recognized as gladii by an average viewer are the various variants of Pompei gladius. After that, in the 2nd century various types of spathae become more popular, although some swords were still short (one might say these are the famous semi-spathae), like for example ring pommeled short swords probably copied from Iazygian and Sarmatian swords... And many "spathae" of the 2nd and 3rd centuries are not that much longer than an average gladius anyway...