They can, but for open-source startups I recommend they do a Show HN first, for the following reasons:
(1) If the Show HN succeeds, then they can save their Launch HN card to play later; if it doesn't succeed, they can go ahead and do a Launch HN soon afterwards.
(2) Show HN is more about the project/tech, especially when it's open-source. Launch HN is more about the startup/business.
(3) Nowadays many startups offer an open-source (or open core) version for free, then make money with a hosted version. For these, it's a good fit to first do a Show HN about the open-source offering, and then later do a Launch HN about the cloud product.
They can, but for open-source startups I recommend they do a Show HN first, for the following reasons:
(1) If the Show HN succeeds, then they can save their Launch HN card to play later; if it doesn't succeed, they can go ahead and do a Launch HN soon afterwards.
(2) Show HN is more about the project/tech, especially when it's open-source. Launch HN is more about the startup/business.
(3) Nowadays many startups offer an open-source (or open core) version for free, then make money with a hosted version. For these, it's a good fit to first do a Show HN about the open-source offering, and then later do a Launch HN about the cloud product.