They are very old and have accrued quite a bit of legacy By release 2.0 of any project, some amount of "legacy" will have been achieved. "Quite a bit of legacy

They are very old and have accrued quite a bit of legacy By release 2.0 of any project, some amount of "legacy" will have been achieved. "Quite a bit of legacy" can be seen as an indicator of platform success. Is the legacy acting as an impediment to future growth or feature development? Is the legacy due to supporting a user base that is neglected by other "modern" projects? The amount of users that get disenfranchised by someones idea of new and modern can be disheartening. There are libraries for languages like PHP, Java and C but these implementations are typically unmaintained and because of the nature of these languages they are not very suitable for the modern cross-platform world. This is a most surprising quote. I am not a PHP expert, but C and Java are quite excellent for use in multi-platform projects. WASM makes C even more relevant for browser hosted code. The author later states that he has implemented a prototype in JavaFX. So much for legacy platforms. There is a lack of libraries implementing these protocols, ... but these implementations are typically unmaintained And now we can begin to understand why. I do not want to make value judgements on the motivation of people desiring to start new projects. It can be fun and liberating. Having the ability to persist and endure while bringing a library or application from prototype, to alpha, beta, 1.0 and beyond is a rare and hard earned skill. And yet, this is exactly the type of skill needed to tackle a problem in the calendar, task and note space.