1.投寄箱：
Dropbox是由美国公司Dropbox Incorporation提供的文件托管服务。它提供云存储，文件同步，个人云和客户端软件。它成立于2007年。Dropbox由两名麻省理工学院的学生Drew Houston和Arash Ferdowsi开发。它仅提供2 GB的可用存储空间。它是最早的云存储服务之一。
2. Ubuntu One：
Ubuntu One是由Canonical Limited提供的文件托管服务，文件同步服务和云服务。这是一个基于OpenID的单点登录服务。它提供了用于在云上存储文件以及从云流式传输音乐的服务。它由Canonical Ltd.开发。适用于Windows，OS X，iOS，Ubuntu和Android。它提供了5 GB的可用存储空间。它于2009年推出。
Dropbox和Ubuntu One之间的区别：
| DROPBOX | UBUNTU ONE |
|---|---|
| It is owned by Dropbox Incorporation. | It was owned by Canonical Limited. |
| It was launched in 2007. | It was launched in 2009. |
| It offers 2 GB free storage space. | It offered 5 GB free storage space. |
| It was developed by Drew Houston and Arash Ferdowsi. | It was developed by Canonical Ltd. |
| It has the unlimited maximum storage size. | Maximum storage size was unlimited here also. |
| It is still in use. | This service was suspended in 2014. |
| Files stored here are encrypted. | Files stored in Ubuntu One were not encrypted. |
| Maximum file size is 10 GB and unlimited using client application. | Maximum file size was 5 GB per file. |
| It is a file hosting, file synchronization and cloud storage service. | It was a commercial file synchronization service. |
| It has traffic or band-width limit of 20 GB per day for free and 200 GB per day for paid. | It has Amazon S3 limits as traffic or band-width limit. |
| It supports Windows, OS X, Linux, iOS, Android and Blackberry. | It supported Windows, OS X, iOS, Ubuntu and Android. |
| It shares files through web applications. | While it shared files through links. |
| It uses block-syncing to update changes quickly. | It did not use block-syncing to update changes quickly. |
| It provides additional 500 MB free storage space for referral up to 18 GB. | It did not have referral system for gaining free additional storage space. |