When I first started running www.ibm.com in 1994 the only realistic browser options were Viola and Mosaic. IBM WebExplorer (OS/2 only at first) showed up and was fairly good but quickly lost out to the Netscape betas. While I was aware of Spyglass I can't remember ever using it.

When MSIE first came out I was explicitly prohibited from using it (typical of IBM at the time). Netscape gets slagged for becoming bloatware but the initial versions were fairly decent and cross–platform. IBM WebExplorer was genuinely not too bad, but it became a victim of IBM internal politics and died a slow death of neglect.

True tidbit which I have no public sources to cite: IBM WebExplorer was the first browser to support scripting, albeit in Rexx, IIRC a couple of months before LiveScript came to Netscape. IBM, in its wisdom, decided not to release that browser, I believe out of concern it might undercut the market for Lotus Notes.