[sheetjs]

If the author is reading this:

> For vim 7.3 and less, it works well for almost all kinds of file formats,

> ie. .xls,.xlam,.xla,.xlsb,.xlsx,.xlsm,.xltx,.xltm,.xlt etc

Someone already pointed it out (https://github.com/yakiang/excel.vim/issues/5) on github: xlrd does not support the XLSB format (and the xlrd authors expressed no interest in building it)

[zzleeper]

I just found out about XLSB.. if really saves me so much time / space, I might just start using it for all large spreadsheets..

[sheetjs]

XLSB is significantly faster to process because it does not require an XML parser to blast through the data. Numbers are stored directly as IEEE754 doubles. Text may end up larger because XLSB uses UTF16LE for everything, including pure-ASCII strings (since Excel uses that format internally, there is no conversion involved and XLSB still will be faster).

The problem you will encounter is that most programs (Numbers, Google Docs) do not support XLSB.

Shameless plug: https://github.com/SheetJS/js-xlsx supports both XLSX and XLSB (AFAICT the only liberally licensed project that handles the format)