What's the best way to export UTF8 data into Excel?

I found that if you set the charset encoding of the web page to utf-8, and then Response.BinaryWrite the UTF-8 Byte Order Mark (0xEF 0xBB 0xBF) at the top of the csv file, then Excel 2007 (not sure about other versions) will recognize it as utf-8 and open it correctly.

After struggling with the same problem for a few hours I found this excellent post on the subject

http://blog.plataformatec.com.br/2009/09/exporting-data-to-csv-and-excel-in-your-rails-app/quote :

So, these are the three rules for dealing with Excel-friendly-CSV:

1. Use tabulations, not commas.
2. Fields must NOT contain newlines.
3. Use UTF-16 Little Endian to send the file to the user. And include a Little Endian BOM manually.

However, if you're using ruby, you problem is solved:first you have the FasterCSV gem

but i ended up using the spreadsheet gem which directly generates excell spreadsheets(i have link limitation, just google spreadsheet + rubyforge)Brilliant !

You're forgetting creating an OleDB datasource and Excel Interop, but there are issues with those as well.

I recommend the SpreadsheetML option. It works pretty well, odds are your platform has some decent tools for building xml files, and it's fully supported as far back as OfficeXP. Office2000 is not supported, but personal experience is that it works in a limited way.