Zotero

It's easy to use EndNote and Zotero together and take advantage of the best features of each, or to share Zotero libraries with colleagues using EndNote or vice versa. Both programs can read and write a standard citation file format called RIS, which means references can be converted back and forth with a few clicks. PDFs and other attachments do not export between programs, however; only citation information

Zotero to EndNote 

To save your Zotero library for importing into EndNote, in Zotero, click File > Export Library. Choose RIS as the file type and pick a filename.

In EndNote, click File > Import. Click the Choose File button and select the file you just exported from Zotero. Set Import Option to Reference Manager (RIS) and click Import.

EndNote to Zotero 

To export your EndNote library for use in Zotero, click File > Export. Set the output style to RefMan (RIS) Export and save it as a text file.

In Zotero, click File > Import. Double-click the file you exported from EndNote. The new references will be added to a collection named "Imported" followed by the date and time.