SQL Developer is written in Java in order to be able to provide a cross platform tool. Using Java means the same tool runs on Windows, Linux and MAC OS X. This provides a uniform interface across platforms. SQL Developer's default connection to the database is using the thin JDBC driver. Defaulting to using the JDBC thin driver means there is no requirement for an Oracle client install minimizing the configuration and footprint. The install for SQL Developer is a simple unzip with a double-click to startup further simplifying the tool.