emerge is a tool to build the kde sources and its third party requirements on MS Windows.
emerge.bat invokes an emerge.py script written in Python, so you first need to install the Python language.
The latest source code for Emerge and the rest of KDE is stored in a Subversion repository.
Check out the sources from the svn-directory of emerge into a new directory, which in this example we will call kderoot. If you have Subversion command-line tool, you can accomplish this with the following command:
svn co svn://anonsvn.kde.org/home/kde/trunk/kdesupport/kdewin32/emerge
Alternatively, you can checkout the sources using a program like TortoiseSVN.
Be sure to use a copy of Subversion that was built on Windows so that checked-out files do not use UNIX line endings. If you check out with UNIX line endings, the patch program will fail when attempting to apply a patch whose line endings don't match the system's.
Create the directory kderoot\etc. Copy the file kderoot\emerge\kdesettings-environment.bat to kderoot\etc\kdesettings.bat and change it according to your needs. Then run it.
Below the directory kderoot\emerge\portage you have the categories as subdirectories which contain individual packages.
To build every required package for e.g. kdebase enter emerge kdebase. If you want to make a dry run, add the option -p to it.
emerge will fetch Windows versions of numerous UNIX-like utilities and libraries from the Internet, putting them in kderoot\bin, then get the Win32 support files, then Subversion, then Perl, the Qt libraries, etc.
emerge is mostly usable together with the kdewin-installer but we're currently still working on some packages which are packaged in a wrong way. It is not recommended to use another layout then installer for directory_layout in the kdesettings.bat anymore (see that file for more detailed information).
You need MinGW to build KDE.
Currently, there is no dependency on MinGW in any of the packages. So, unless you call emerge mingw manually, or alter the environment configuration scripts to add your existing MinGW bin directory to the PATH variable, compiling anything will choke. If you run emerge mingw, you will not need to modify the environment configuration scripts to point to a custom location.
If you see an error about cc1plus not being found, either add MinGW's \libexec\gcc\mingw32\3.4.5 to your PATH variable or copy the contents of this directory to MinGW's bin directory. The prior is preferred.