> The package I wanted is <specfont>. It is included in Texlive 2012, but > doesn't work. When \usepackage{specfront}, Texmaker returns an error. As I see it, there is no package 'specfont' on CTAN. If you meant 'fontspec' for changing fonts in LaTeX documents, you have to use 'lualatex' rather than 'pdflatex' for generating pdf-documents.