Sharing terminology can only bring more benefits. It helps improving consistency, uniformity and reliability of data.
The sharing of existing terminological data helps translators, terminologists, researchers (but I would not exclude students, journalists, web writers and whoever works with knowledge) to use the right terms even without being experts and preventing them from spending too much time looking for resources, extracting terms and checking their reliability.
Here a list of my favourite resources:
TAUS Data: a cloud platform based on shared translation memories. I use almost every day TAUS Data for technical translations and thank to it I can choose the right term by checking the context (always reliable) and being sure I have selected the right term even without being an expert on the particular subject.
Taas - Cloud Services for Terminology Work: New look for this cloud based portal providing multilingual and collaborative terminology services. Beta version for now, flat design, scroll-down layout, the look of a start-up website expressing the innovative attitude of this project funded by the European Commission and managed by Tatiana Gornostay. By logging-in it is possible to access to the tools such as a look-up tool, a term extractor providing term candidates from various sources, and the possibility to share your terminology with other users.
TermWiki.com: is a collaborative terminology portal that allows users to search, upload, translate and share terms and definitions with other users. I have to say that the staff behind this portal is really nice, friendly and always ready to help you to improve their tools to better suit your needs. My favourite tool is the TermWiki GlossaryWidget and I have one on this blog.