Nmap uses Subversion, the famous Version Control System (VCS), to manage the source code of the project. First, make sure you have a Subversion client at hand:

$svn --version

On Debian-based systems, you can install Subversion by running the following command:

#apt-get install subversion

Once the Subversion client is installed, we grab the development branch from the official repositories with the following command:

$svn co https://svn.nmap.org/nmap

The preceding command downloads the latest revision of the development branch into a new directory in your current directory. We will refer to this folder as your working copy. Before compiling, you may need additional tools and libraries such as OpenSSL. Make sure you have all the requirements installed by running the following command:

#apt-get install make g++ libssl-dev autoconf

Now we can compile and install Nmap. Go to the nmap directory that was just created by Subversion and enter the following command:

$./configure

If everything worked correctly, you should see an ASCII dragon warning you about the power of Nmap, like this:

Now let's compile Nmap with the following commands:

$make
#make install

Now run Nmap to ensure that it was installed correctly. You should see your build information:

#nmap -v
Nmap version 6.47SVN ( http://nmap.org )
Platform: x86_64-apple-darwin14.0.0
Compiled with: nmap-liblua-5.2.3 openssl-0.9.8za nmap-libpcre-7.6 libpcap-1.5.3 nmap-libdnet-1.12 ipv6
Compiled without:
Available nsock engines: kqueue poll select

To update your working copy, use the following command inside your working directory:

$svn up

Once your working copy is synchronized with the remote repository, we need to rebuild Nmap:

$make

Again to install the binaries and data files in the system, use this command:

#make install