WSO2 Identity Server might be a bit more popular than Optimal IdM. We know about 1 link to it since March 2021 and only 1 link to Optimal IdM. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
Theoptimalcloud.com seems to redirect to https://optimalidm.com which appears legitimate. Source: over 1 year ago
Try WSO2 Identity Server, it's open source: https://wso2.com/identity-and-access-management/. Source: about 3 years ago
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