3. Despite fine-tuning on Python, StarCoder remains competitive on most languages, and
also outperforms other open models. What is more surprising is that StarCoder slightly
outperforms StarCoderBase on certain languages, despite being fine-tuned on Python. At
this time, we can only speculate on why this is the case, and further investigation of the open
training data is likely to help shed light on this finding.

There are several other conclusions that we can draw from the table. For example, CodeGen-16B-
Multi performs better than one might expect on some languages that are reportedly not in its training
set, including C#, Lua, PHP, and TypeScript. Its performance on TypeScript is less surprising since
simple JavaScript functions often type-check with TypeScript by design. Similarly, StarCoder shows
high performance on Swift, even though it was not included in its training set, as explained in
Section 3.1.
StarCoder_paper (1)