from a recent post by  AJ Tarachanowicz

I know Eclipse IDE [1] detects and allows you to set file encoding along with an HTML Tidy ability, CVS Clients, SSH Client, DB Client, Visual Diff (CVS vs Current History, Local History, Another Project, Different CVS), and the standard IDE feature.

With the release of Eclipse 3.0 it has definitely come a long way from 2.x. There are also serveral plugins avaliable for CSS, (X)HTML, php[2], phpDocumentor [3] struts, perl, an abundant amount of java plugins, UML, and much much more [4][5]. It’s open source and it receives major support from major industry leaders such as IBM, Borlan, QNX Software Systems, Red Hat, SuSe, and Oracle just to name a few [6].

[1] http://www.eclipse.org – Eclipse IDE
[2] http://www.phpeclipse.de – PhpEclipse
[3] http://www.xored.com/download.php – TruStudio IDE
[4] http://www.eclipse.org/tools/index.html – Eclipse Tools
[5] http://www.eclipse.org/community/plugins.html – Eclipse Plugins
[6] http://www.eclipse.org/org/index.html – History of Eclipse