There are several popular ecommerce platforms available that can be considered the best for launching an ecommerce store. The choice of the platform depends on various factors such as budget, technical expertise, scalability, customization options, and specific business requirements. Here are some of the top ecommerce platforms:

1. Shopify: Shopify is one of the most popular and user-friendly ecommerce platforms. It offers a wide range of features and templates, making it easy for beginners to set up and manage their online store. Shopify also provides a secure and reliable hosting infrastructure, integrated payment gateways, and excellent customer support. It is suitable for small to medium-sized businesses. (Reference: https://www.shopify.com/)

2. WooCommerce: WooCommerce is a plugin for WordPress, which is a widely-used content management system (CMS). It provides a flexible and customizable platform for ecommerce, allowing users to leverage the extensive WordPress ecosystem. WooCommerce offers a range of themes, extensions, and integrations, making it suitable for businesses of all sizes. It is particularly advantageous for those already using WordPress for their website. (Reference: https://woocommerce.com/)

3. Magento: Magento is a robust and scalable ecommerce platform suitable for large businesses with complex requirements. It offers a high level of customization, advanced features, and excellent performance. Magento provides options for both self-hosted and cloud-based solutions, allowing businesses to choose according to their needs. It is known for its extensive community and marketplace for additional extensions. (Reference: https://magento.com/)

4. BigCommerce: BigCommerce is a feature-rich ecommerce platform that caters to businesses of all sizes. It offers a wide range of built-in features, including hosting, security, payment gateways, and marketing tools. BigCommerce provides a user-friendly interface, extensive customization options, and excellent scalability. It is known for its strong SEO capabilities and integration with various third-party applications. (Reference: https://www.bigcommerce.com/)

5. Squarespace: Squarespace is a popular website builder that also offers ecommerce functionality. It provides visually appealing templates, a user-friendly interface, and reliable hosting. Squarespace is suitable for small businesses or individuals who want an easy-to-use platform with basic ecommerce features. It is known for its design-centric approach and simplicity. (Reference: https://www.squarespace.com/)

Ultimately, the best ecommerce platform for launching an ecommerce store depends on the specific needs and goals of the business. It is advisable to thoroughly research and evaluate each platform's features, pricing, customer support, and user reviews before making a decision.