What is an ECCN?
ECCN stands for Export Control Classification Number; see:
These numbers are assigned through the US Export Administration Regulations (EAR), part of the US Bureau of Industry and Security (BIS), which is a branch of the US Department of Commerce. The EAR describe the export rules and restrictions on a wide range of commodities, technologies, and software. This document is no substitute for understanding those regulations; the ProFTPD Project cannot anticipate how they might apply to third party distributions or for specific export decisions made by those parties. End-user, end-use and country of ultimate destination may affect export licensing requirements.

According to the
current regulations and descriptions, the ProFTPD Project software products fall into the category of "publicly available" encryption software and source code, and are thus classified as ECCN 5D002.

Products classified as ECCN 5D002 are exported by the ProFTPD Project under the License Exception TSU in EAR 740.13(e), which applies to software containing or designed for use with encryption software that is publicly available as open source. License exception TSU further provides that:

Posting encryption source code and corresponding object code on the Internet (e.g., FTP or World Wide Web site) where it may be downloaded by anyone neither establishes "knowledge" of a prohibited export or reexport for purposes of this paragraph, nor triggers any "red flags" necessitating the affirmative duty to inquire...
Note that exporters other than the ProFTPD Project within the US may or may not be eligible for exception TSU, and it is each specific exporter's responsibility to understand and comply with all export regulations applicable within their jurisdiction.

Cryptographic Components
The ProFTPD Project source code distributions include cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. BEFORE using any encryption software, please check your country's laws, regulations and policies concerning the import, possession, or use, and re-export of encryption software, to see if this is permitted. See for more information.

The U.S. Government Department of Commerce, Bureau of Industry and Security (BIS), has classified this software as Export Commodity Control Number (ECCN) 5D002, which includes information security software using or performing cryptographic functions with asymmetric algorithms. The form and manner of this ProFTPD Project distribution makes it eligible for export under the License Exception ENC Technology Software Unrestricted (TSU) exception (see the BIS Export Administration Regulations, Section 740.13e) for source code.

The following lists the modules, included in the source distributions, which explicitly include/use cryptographic code:

which effectively removes ECCN 5D002 from the EAR, effective January 7, 2011.

A similar question came up for Mozilla; this blog post (now a bit dated) explains things further:

The Apache Software Foundation (ASF) page on this topic is also quite relevant:

And the text of EAR Section 740, for those interested:

$Date: 2013-07-09 17:41:49 $