Coming from the windows world people tend to get used to big programs that do everything, using word or excel makes you feel like your program should do everything, a word processor should format, spell check and print your files; a spreadsheet should do all the sorting, mathematical functions and graphing.

Plan 9 and its Unix ancestors don't work like this. Programs in Plan 9 are meant to have one use and one use only. Plan 9 doesn't have word processors, instead you write the text using a text editor(liked ed(1), acme(1) or sam(1)), format it with fmt(1) and if you want to turn it into a form that's document quality insert ms(6) macros.

excel requires a bit more understanding, spreadsheets are represented as flat files, you can manipulate these files, summations, equations etc. with a programming language called awk(1) which specializes in manipulating structured text. Once manipulated you can graph data with a graphing program called graph(1) manipulation on fields isneed to use graph(1) if you want to write to the screen or grap(1) if you want to make troff graphs to include in your documents.

But if you were just limited to mimicing the functionality of windows Plan 9 would only be a cumbersome equivalent. The real joy of Plan 9 is the ability of each of these programs to interact with each other, since everything is flat text