Rain in your terminal. Run with `php Rain.php`

Rain.php

<?php

/**
 * Renders rain. The code was like 10 times shorter before moving it into the class
 */
class Renderer
{
  protected $width, $height, $text;

  private $_middle, $_textBeginPos, $_textLength, $_line;

  private $_resetPos;

  public function __construct($width, $height, $text)
  {
    $this->width = $width;
    $this->height = $height;
    $this->text = $text;
  }

  protected function init()
  {
    $this->_middle = (int)floor(($this->height - count($this->text)) / 2);
    $this->_textParams = array();
    foreach ($this->text as $text) {
      $this->_textParams[] = array(
        'length' => mb_strlen($text),
        'pos' => (int)floor(($this->width - mb_strlen($text)) / 2),
      );
    }
    $this->_line = str_repeat(' ', $this->width);
    $this->_resetPos = `tput cup 0 0`;
    for ($i = 0; $i < $this->height; $i++) $this->_positions[$i] = array();
    $this->_collisions = array();
    $this->clearScreen();
  }

  protected function clearScreen()
  {
    echo `tput clear`;
  }

  protected function renderFrame()
  {
    echo $this->_resetPos;
    $lines = array();
    for ($i = 0; $i < $this->height; $i++) {
      $curLine = $this->_line;
      foreach ($this->_positions[$i] as $p) {
        $curLine[$p] = '/';
      }

      $lines[] = $curLine;
    }

    // Text
    foreach ($this->_textParams as $i => $params) {
      $lines[$this->_middle + $i] = substr_replace(
        $lines[$this->_middle + $i],
        $this->text[$i],
        $params['pos'],
        $params['length']
      );
    }

    // Collisions
    foreach ($this->_collisions as $collision) {
      $lines[$collision[0]][$collision[1]] = '*';
    }
    echo implode("\n", $lines) . "\n";
  }

  protected function nextFrame()
  {
    // Collisions
    $this->_collisions = array();
    foreach ($this->_positions[$this->height - 1] as $p) {
      $this->_collisions[] = array($this->height - 1, $p);
    }

    // Move all drops one line below and shift them to the left
    for ($i = $this->height - 1; $i > 0; $i--) {
      $this->_positions[$i] = array();
      foreach ($this->_positions[$i - 1] as $p) {
        if ($p > 0) {
          $this->_positions[$i][] = $p - 1;
        } else {
          $this->_positions[$i][] = $p - 1 + $this->width;
        }
      }
    }

    // Add a line with random drops to the top
    $this->_positions[0] = array();
    $drops = mt_rand(0, 8);
    while ($drops--) {
      $this->_positions[0][] = mt_rand(0, $this->width - 1);
    }
  }

  public function run()
  {
    $this->init();
    // Initial rain lines
    for ($i = 0; $i < $this->height - 10; $i++) $this->nextFrame();
    while (true) {
      $this->renderFrame();
      $this->nextFrame();
      usleep(45000);
    }
  }
}

$text = array(
  'Rain in your terminal', '',
  'Running on PHP ' . PHP_VERSION
);
$r = new Renderer(80, 25, $text);
$r->run();