The best replacement for opencart is magento.

The best alternatives to opencart are rated as following:
★★★★★  magento
★★★★★  prestashop
★★★★  oscommerce
★★★  woocommerce
★★★  shopify
★★  zencart
★★  virtuemart
★  tomatocart
★  zen cart
★  cs-cart
★  wordpress ecommerce
★  cubecart
★  mijoshop
★  nopcommerce
  x cart
  x-cart
  ubercart
  presta
  magento is better
  magenta

Your alternative for opencart is not listed? Suggest!
Speaking about opencart, one probably shouldn't forget about ccavenue.

Other search terms related to opencart and their ratings are:
★★★★★ ccavenue
You have in mind a companion for opencart and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of opencart in all years. Click on graph for more.
opencart
magento
prestashop