Alternative to "Vote Up Down" module for? Is there any other module like vote_up_down, but for Drupal 7? This one has a development version but as the author says it is unstable. 


  7.x (unstable, on development, do not use this version for production)
Use the Fivestar module for rating. Or the Rate module. Some more details about these modules (quotes included are from their project pages):


Fivestar:


  ... adds a clean, attractive voting widget to nodes and comments and any entity. It features:
  
  
  jQuery rollover effects and AJAX no-reload voting
  Configurable star sets
  Graceful degradation to an HTML rating form when JavaScript is turned off
  Support for anonymous voters
  Spam protection to keep users from filling your DB with bogus votes
  Easy-to-use integration with Views module for lists sorted by rating, or filtered by min/max ratings
  A Fivestar CCK field for use in custom node types
  An easy-to-use Form API element type for use in other modules
  Compatible with all versions of jQuery (1.0 - 1.8)
  

Rate:


  ... provides flexible voting widgets for nodes and comments. "The cck model for voting with Drupal".