Popular blogging services like Wordpress and Drupal provide the infrastructure needed to create websites and blogs in Welsh. These offer themes that are tailored to Welsh - you can see more examples on the website meddal.com.
Hedyn.net also has Welsh podcasts.
The Centre for Community Journalism creates resources to help learn skills, build confidence to enable anyone to create and share more news within their communities through the medium of Welsh using digital and social media.
If you have information or expertise to share you can contribute articles in Welsh on Wicipedia Cymraeg.
When you write content in Welsh, remember that the Cysill Online spelling and grammar checkers are free and very useful.
Programming and Coding
The Language Technologies Unit at Bangor University's Canolfan Bedwyr provides a range of material including resources and translation technologies. The team is also developing a speech corpus for the Welsh language called GALLU.
The Welsh National Language Technologies Portal provides these resources as 'building blocks', open and free for Welsh coding clubs, hackers, enthusiastic volunteers, software companies (local and international) and researchers to create finished digital products in Welsh.
Raspberry Pi Cymraeg is a Welsh language resource to teach people how to code.