There are plenty of decent free editors for Linux, probably more so than any other OS around, but one which seems to fall somewhere between an editor and an IDE is Komodo Edit from ActiveState.
Komodo Edit is very decently equipped with some nice features to be found hidden within its functionality. Support for Node.js is a recent addition and the full list is quite impressive.
Full debugging, code intelligence and editing for Python (including Python 3), PHP, Perl, Ruby, Tcl, XSLT and Node.js.
Komodo Edit has editing for dozens of other languages, including C/C++, JSON, SQL, Erlang, CoffeeScript, LESS, SCSS and others.
Add to that Fast Open, Vi key bindings and a Toolbox and you have an extremely useful editor for your web projects.
Note, you will have to have the languages you wish to use installed on your system before they become available in Komodo.
To install Komodo Edit on your Centos 6/RHEL box first go to the ActiveState site and download the Linux version to your home directory.
Change privileges and move to the opt directory
$ sudo su
# cd /opt/
Untar the downloaded tar file.
# tar xvf /home/<user_name>/Komodo-Edit-8.0.1-12353-linux-x86.tar.gz
Move into /opt/Komodo-Edit-8.0.1-12353-linux-x86
# cd Komodo-Edit-8.0.1-12353-linux-x86/
(or whatever version you use)
Run the install shell script
You will go through a series of questions with an option to change the install directory, change this to '/opt/komodo'. When the process is complete you will be given a $PATH variable which you can put in to your /home/<user>/.bashrc file
# vi /home/<user>/.bashrc
See vi and vim commands
Enter into it as below under user specific entries
Save & exit vi then
# source /home/<user>/.bashrc
Run it with
(You can also place the export line in a separate 'komodo.sh' script in the /etc/profile.d/ directory )
See Fluxbox key bindings if you are using Fluxbox.
To add it to your right click context menu if it isn't already there you should just right click on any text file and browse to /usr/local/bin/komodo.exe - this should add it.
There are a wide range of Plugins, Extensions and Add-ons available including an API to write your own if you wish.
If you use it with a Lamp server stack, Komodo Edit makes a decent web development tool, with a handy preview either in a Komodo tab or using your installed browsers and a mapping to your server which you can set up in the preferences dialogue, along with Remote Servers, Stackato and much more.
Overall, Komodo Edit makes a very useful addition to your Linux Desktop and while it is not a replacement for the likes of Eclipse, you will almost certainly find features of it that make it invaluable for quite a few tasks.
I would definitely recommend giving it a try if you are looking for a development tool to fill in certain gaps in your armoury.