IBM has donated translations from their products to Eclipse. The
language packs group translations for several languages into a single
download which are distributed as a set of features which you can
install by extracting over your Eclipse directory and restarting
Eclipse. Specifically,

NLpack1- Contains the NL fragments and the NL features that contain
those fragments for: German, Spanish, French, Italian, Japanese,
Korean, Portuguese (Brazil), Traditional Chinese and Simplified
Chinese.

NLpack2- Contains the NL fragments and the NL features that contain
those fragments for: Czech, Hungarian, Polish and Russian.

NLpack2a- Contains the NL fragments and the NL features that contain
those fragments for: Danish, Dutch, Finnish, Greek, Norwegian,
Portuguese, Swedish and Turkish.

NLpackBidi- Contains the NL fragments and the NL features that contain
those fragments for: Arabic and Hebrew.

These translations are based on the Eclipse 3.2 build but should work
with all subsequent 3.2.x maintenance releases. If new strings are
added to Eclipse after 3.2, they will not show up as translated in the
3.2.x stream when you install this language pack.

http://download.eclipse.org/eclipse/downloads/drops/L-3.2.1_Language_Packs-200609210945/index.php