It's free, but read on.
GWT Highcharts is offered for free and as an open source project under the Apache license. If you like this software and intend to use it we'd appreciate you letting us know, and possibly adding a link or reference back to our site. To support the ongoing development and maintenance of this project please consider making a donation.
Apache license, Version 2.0
Copyright © 2011 Moxie Group
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Highcharts and Highstock
Both Highcharts and Highstock are licensed for free for any personal or non-profit projects under the Creative Commons Attribution-NonCommercial 3.0 License.
For commercial, corporate or government use a license is required, which can be purchased for as little as $80. See the license and pricing details directly on the Highcharts site for more details.