I wonder if there is some free solutions for typing math formulas in LaTeX way in Microsoft word document (Office 2007)?

You can use Latex in Word. It provides macros for Microsoft Word that allow the use of LaTeX input to create equations images in both inline and display modes without having to install any software on the local computer. As far as I know, this is the only free alternative to the paid programs like Aurora and TexPoint. For Office 2007, go to Latex in Word Project Page on Source Forge, and click on Word 2007 under Files.



I prefer TeXsword over Latex in Word (http://sourceforge.net/projects/texsword/). It has all the features of Latex in Word, plus gives handling of equation references. And it doesn't require the Internet connection, which I see as a feature not a limitation: MikeTeX isn't that big after all, and having the LaTeX locally allows you typing your document when traveling. 


The question asked about "typing math formulas in LaTeX way in Microsoft word document (Office 2007)." But the responses and comments to date actually answer a different question  how to embed an actual LaTeX processor into Word. Very few people realize that the builtin equation editor in Word 2007 actually understands LaTeXstyle equation entry. Simply insert a new equation, and then type LaTeX into it. As you type, Word will built up a graphical representation of the equation. Once it appears in the GUI, you can no longer edit it as LaTeX. Word does not have an embedded TeX processor  it's just doing pattern matching to convert simple LaTeX syntax into the native equation format. You should therefore not expect to get perfect fidelity for supercomplex LaTeX equations. However, it's enough for probably anyone but a mathematician, and it's a lot faster than clicking elements with the mouse. The Word 2007 equation editor also has a linear equation entry format, which is fairly intuitive and does not require familiarity with LaTeX. For example, typing in Notes:


