The above mentioned apps use the "Hunspell" library, which can be used directly under PHP without the usage of ugly (and unsecure) exec/system calls.
The following steps I did on my OSX MPB (10.10 / Yosemite) but they will be very similar on any Linux/Unix system (well, might even be easier on Ubuntu or Debian via their package system).
Just make sure you at least use libenchant 1.5
Compile and Install hunspell
$ wget http://downloads.sourceforge.net/hunspell/hunspell-1.3.3.tar.gz $ tar xvfz hunspell-1.3.3.tar.gz $ cd hunspell-1.3.3 $ ./configure $ make $ sudo make install
Compile and Install libenchant
$ wget http://www.abisource.com/downloads/enchant/1.6.0/enchant-1.6.0.tar.gz $ tar xvfz enchant-1.6.0.tar.gz $ cd enchant-1.6.0 $ ./autogen.sh $ ./configure $ make $ sudo make install
Compile and Install php-enchant (in this case as shared lib)
(there is currently a bug in the configure file that will not recognize your libenchant version and thus not giving you some of the newer features, patch is here)
$ cd php-5.5.14/ext/enchant/ $ phpize $ ./configure $ make $ sudo make install
Something something extension=enchant.so in your php.ini... Dictionaries
$ cd Dicts $ sudo wget https://chromium.googlesource.com/chromium/deps/hunspell_dictionaries/+archive/master.tar.gz $ sudo tar xvfz master.tar.gz