There is actually no problem with Eclipse PDT. The reason some users have it very slow is that these users haven't done the important project configuration.
Every project has validators. Many of them can be safely disabled, other are relevant only for a small fraction of the project and irrelevant for the rest. For example, application framework shouldn't be scanned for TODO's, HTML syntax validity, XML syntax validity, PHP errors, and similar. Only the actual project should be scanned.
This needs to be configured per project. Rebuilding workspace then takes up to 5 seconds (if it's a large project).
Here is the suggested performance optimization:
- Right click project
- Select properties
- Select validation
- Check Enable Project specific settings
- On any Validator row, click the '...' button
- Select Exclude Group
- Click Add rule
- Select 'Folder or file name'
- Click Next
- Select files or folder which don't need any validation (i.e. 3rd-party files in your project).
- Click Finish
- Click OK
- Click OK
Repeat the above for all current validators, or simply disable unwanted validators completely.
In addition, follow the Zend Studio performance optimization. It applies to PDT just as well:
Portions borrowed from http://stackoverflow.com/questions/783902/excluding-disabling-validation-in-eclipse
Since I believe there is no mistake in eclipse (and PDT), the question no. 2 is not applicable here. Note that PDT is not a PHP IDE. It is a plugin for Eclipse which adds PHP support. Eclipse is a development platform. It's robust, configurable, scalable.
Bottom end: users should be able to configure their projects to use only what they need.