Here is a set of tools I use, and some project work I done
Oracle Apex
Oracle Apex is a Oracle hosted rapid web application development tool using only an internet browser. I have been using this tool for a while and I find it very easy to use. Oracle Apex is all-in-the-database approach to application development, as application server and the webserver server are inside and are part of the Oracle database. I have an Oracle Apex test workspace hosted by Oracle. This is a free service and anybody can get an account with Oracle Apex for testing and evaluation purposes. To sign up for a FREE Oracle Apex development account go to Oracle Apex and sign up. My development site is here: Kubilay's Oracle Apex Development Website
Developer force and Salesforce
Developer Force is a free developer program for the Force.com Cloud computing Platform from Salesforce. You can get a force.com account anytime and is free. I have used this platform at work to create fault tracking and Google Maps based applications. Force.com is like Oracle Apex, a web application development environment where you do declarative programming and create apps by using just an internet browser. In the core of this technology you find a database (Oracle) and a Java like code called APEX Code and API’s. Check it out here: developer.force.com>
Informatica
A great integration environment in the Cloud. You can connect hetergeneous databases, spreadsheets, csv and cloud-computing platforms like Salesford and move data between them. A kind of ETL tool in the Cloud. Informatice is an enterprise-class software-as-a-service (SaaS) integration application. They even give you 1 connecter free! Find out more here: informaticaondemand
Oracle SQL Developer
Oracle SQL Developer is a free and fully supported graphical tool for database development. With SQL Developer, you can browse database objects, run SQL statements and SQL scripts, and edit and debug PL/SQL statements. You can also run any number of provided reports, as well as create and save your own. SQL Developer enhances productivity and simplifies your database development tasks. Find out more about Oracle SQL Developer
Talend TOS
Like Informatica Talend is another company focusing in data integartion solutions. The difference is that Talend Open Studio is Open Source and is absolutely free! I have used Talend TOS to integrate data between Salesforce, Oracle and MS SQL Server. It is quite fun to use as is very graphical and very easy to understand. It can generate ETL scripts which you can host anywhere and run. It can generate the ETL scripts in Java or Perl and is based on Eclipse. Have a look here to find out more. www.talend.com
Apatar
Apatar is a company focusing in data integration. Is yet another Open Source data integration tool like Talend TOS. This tool is very graphical too. I have used Apatar like Talend TOS in data integration between Oracle and MS SQL Server. It works with Salesforce too, plus it has many other connectors. Find out more here: http://www.apatar.com