Open-source content management system, Drupal, got another boost today when Boston-based Acquia announced it has raised $55 million in venture capital. “At Acquia, we pride ourselves on guiding today’s leading organizations as they digitalize their business,” Acquia CEO Tom Erickson said in a statement. While the latest investment is a sign of confidence in the company, it’s also worth noting that back in 2012, while raising a round of $30 million, Acquia said it was closing in on an IPO. Those plans have obviously been shelved. Acquia was cofounded by Belgium-born Dries Buytaert, who now serves as chief technology officer. Buytaert created Drupal...