Systems and methods for installing and upgrading application packages to an application platform. Application packages may be uploaded to a directory by developing users (developers) for installation by subscribing users (subscribers). Alternatively, a developer may send identification information to a subscribing user to allow that user to access and install that application package created by the developer. Application packages may also be upgraded. If a developer changes the original source package, a subscriber can choose to pull into their organization the change(s) made by the publisher while preserving any data rows the subscriber had created since first importing the package.