Yoshikoder is described as 'The Yoshikoder is a cross-platform multilingual content analysis program developed as part of the Identity Project at Harvard's Weatherhead Center for International Affairs'. There are four alternatives to Yoshikoder for Windows, Mac and Linux. The best alternative is TextSTAT, which is free. Other great apps like Yoshikoder are Linguistic Inquiry and Word Count (Paid), Antconc (Free) and WordSmith Tools (Paid).
TextSTAT is a simple programme for the analysis of texts. It reads plain text files (in different encodings) and HTML files (directly from the internet) and it produces word frequency lists and concordances from these files.
AntConc is a freeware, multiplatform tool for carrying out corpus linguistics research and data-driven learning. It runs on any computer running Microsoft Windows (tested on Win 98/Me/2000/NT, XP, Vista, Win 7)