Doesn't TurboCalc open Excel files? Can't check now... but I guess M$ has invented dozen of new formats for xls after last update to TurboCalc
But older versions could work.
For pdf I've used apdf and especially the MorphOS version of it works pretty well with most pdf files.
I guess there's many converters for Excel and Word files... I think there was free online web services for that purpose too. But it's really rare when I need to handle them, so I don't know better
For mail I use Pine on my mail server. Works always no matter what computer is in front of me
Only thing I need is ssh and that I can get on every system
